IT Security and Linux System Administration Quiz

Study Flashcards Play Quiz

Questions and Answers

What is the purpose of the `uid` option in the `mount.cifs` command?

To specify the user that appears as the local owner of the files

Which of the following is a good practice for private key security?

Creating private keys on the systems where they will be used

What is the main purpose of NSEC3 in DNSSEC?

To prevent zone enumeration

What is the command used to change the SELinux context for a user?

newrole Signup and view all the answers

Which file is used to configure the AIDE system?

/etc/aide/aide.conf Signup and view all the answers

What is the purpose of the `ndpmon` command?

To monitor the network for neighbor discovery messages from new IPv6 hosts and routers Signup and view all the answers

Which of the following is a good practice for private key security?

Storing private keys in a secure location Signup and view all the answers

What is the purpose of the `mount.cifs` command?

To mount a CIFS file system Signup and view all the answers

What is the purpose of rkhunter?

To detect rootkits and other security threats Signup and view all the answers

Which command is used to view the access control list of a file?

getfacl Signup and view all the answers

What is a man-in-the-middle attack?

An attack that intercepts communications between two parties to steal information Signup and view all the answers

Which permission bit allows a user to delete a file?

Write Signup and view all the answers

What is the purpose of a Certificate Authority (CA)?

To issue digital certificates to organizations Signup and view all the answers

Which command adds users using SSSD’s local service?

sss_useradd Signup and view all the answers

Which DNS records are used in DNSSEC?

RRSIG Signup and view all the answers

Which of the following terms refer to existing scan techniques with nmap?

FIN Scan Signup and view all the answers

Which command changes the source IP address to 192.0.2.11 for all IPv4 packets which go through the network interface eth0?

iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to-source 192.0.2.11 Signup and view all the answers

Which of the following methods can be used to deactivate a rule in Snort?

By placing a pass rule in local.rules and restarting Snort Signup and view all the answers

What is the primary function of the tool that reads syslog files containing Snort information?

To generate port scan statistics Signup and view all the answers

Which command is used to delete the first key from a LUKS device?

cryptsetup luksDelKey /dev/sda1 1 Signup and view all the answers

What is a characteristic of eCryptfs?

It cannot be used to encrypt directories on a Linux system Signup and view all the answers

How does TSIG authenticate name servers for secured zone transfers?

By using a secret key that is shared between the servers Signup and view all the answers

Which of the following is NOT a component of FreeIPA?

Intrusion Detection System Signup and view all the answers

What is the purpose of the dnssec-keygen utility?

To generate DNSSEC keys Signup and view all the answers

What type of system is a Security Information and Event Management (SIEM) system?

HID system Signup and view all the answers

What information is contained in an X509 certificate?

Basic constraints, including whether it is a CA Signup and view all the answers

What command is used to make the contents of an eCryptfs encrypted directory available to the user?

ecryptfs-mount-private Signup and view all the answers

What is the purpose of the chage command?

To disable the automatic password expiry for a user Signup and view all the answers

What does a network link monitor do?

Queries network interfaces Signup and view all the answers

What is an asymmetric key used for?

Encryption and decryption with a pair of keys Signup and view all the answers

What is an example of a behavioral-based HID technique?

Anomaly-based detection Signup and view all the answers

What command revokes ACL-based write access for groups and named users on a file?

setfacl ~m mask: : rx Signup and view all the answers

What is the purpose of the setfattr command?

To set an extended attribute on a file Signup and view all the answers

What is a buffer overflow?

A type of software vulnerability Signup and view all the answers

What tool can be used to manage the Linux Audit system?

auditd Signup and view all the answers

What is the main difference between a DNSSEC-signed zone and a non-DNSSEC-signed zone?

The zone signing key is used to sign the DNS records Signup and view all the answers

What is the difference between a SetUID and SetGID bit?

SetUID allows a file to be executed with the permissions of the file owner, while SetGID allows a file to be executed with the permissions of the group owner Signup and view all the answers

What is a honeypot?

A decoy system to detect and deflect attacks Signup and view all the answers

What is the primary purpose of a Certificate Revocation List (CRL)?

To revoke compromised X.509 certificates Signup and view all the answers

What package management tools can be used to verify the integrity of installed files on a Linux system?

RPM and DPKG Signup and view all the answers

What is the main benefit of using AppArmor over SELinux?

AppArmor is less complex and easier to configure Signup and view all the answers

What is the primary purpose of a DNSKEY record in DNSSEC?

To sign a DNS zone Signup and view all the answers

What is the main difference between a chroot environment and a regular environment?

A chroot environment is more secure than a regular environment Signup and view all the answers

What is the primary purpose of AIDE?

To detect intrusions and system changes Signup and view all the answers

What is phishing?

A type of social engineering attack Signup and view all the answers

What is the primary purpose of DNS over TLS and DNS over HTTPS?

To provide secure communication between DNS clients and servers Signup and view all the answers

What is the main difference between AppArmor and SELinux?

AppArmor is implemented in user space, while SELinux is implemented in the kernel Signup and view all the answers

What is the primary purpose of an X.509 certificate?

To verify the identity of a website Signup and view all the answers

What is the purpose of the Linux Audit system?

To detect intrusions and system changes Signup and view all the answers

What is the purpose of file ownership in Linux systems?

To restrict access to files only to their owner Signup and view all the answers

What is a Trojan?

A type of malware that disguises itself as legitimate software Signup and view all the answers

What is the purpose of a trust anchor?

A root certificate that is trusted by a particular CA Signup and view all the answers

Which of the following is used to issue and sign X.509 certificates?

To issue and sign X.509 certificates Signup and view all the answers

What is the purpose of the command dnssec-keygen?

To generate DNSSEC keys Signup and view all the answers

What is a rogue access point?

An unauthorized access point that is set up to look like a legitimate one Signup and view all the answers

What is the purpose of the push directive in an OpenVPN server configuration?

To send network configuration information to the client Signup and view all the answers

What is Linux Malware Detect?

A tool to detect malware on a Linux system Signup and view all the answers

What is a DoS attack?

An attack that floods a network or server with traffic to make it unavailable Signup and view all the answers

What is the primary purpose of a honey pot in network security?

To lure attackers into a trap and detect their activities Signup and view all the answers

Which type of DNS server is responsible for performing DNSSEC validation on behalf of clients?

Recursive name server Signup and view all the answers

What is the purpose of the ipa trust-add command in FreeIPA?

To establish a trust between a FreeIPA domain and an Active Directory domain Signup and view all the answers

What is the purpose of the ntop command with the --set-admin-password option?

To set the administrator password for ntop Signup and view all the answers

What is a symmetric key in cryptography?

A key used for encryption and decryption that is the same Signup and view all the answers

What is the purpose of the pam_cracklib PAM module?

To check new passwords against dictionary words and enforce complexity Signup and view all the answers

What is the purpose of TSIG in DNS?

To sign DNS messages for secure communication Signup and view all the answers

What is the purpose of IP sets in Linux?

They group together IP addresses that can be referenced by netfilter rules Signup and view all the answers

What is the purpose of an extended attribute in Linux?

To store additional metadata about a file Signup and view all the answers

What is the effect of the iptables command with the -A INPUT option?

Accept all TCP traffic on port 20 and 21 for a specific IP address Signup and view all the answers

What is the purpose of OCSP stapling?

A mechanism that allows a server to provide proof of the revocation status of its own SSL/TLS certificate Signup and view all the answers

What is the main purpose of HID?

To detect and respond to security incidents Signup and view all the answers

What is a ciphertext?

The encrypted message Signup and view all the answers

What is the command to install and configure a new FreeIPA server?

ipa-server-install Signup and view all the answers

What is Cryptography?

The art of sending secret messages Signup and view all the answers

What is the purpose of the ebtables command?

To display ebtable rules Signup and view all the answers

What is a rootkit?

A type of malware that disguises itself as legitimate software Signup and view all the answers

What is the purpose of the openssl command?

To generate a certificate signing request (CSR) Signup and view all the answers

What is the protocol commonly used to transmit X.509 certificates?

LDAP Signup and view all the answers

What is a plaintext?

The original message before encryption Signup and view all the answers

What is the purpose of a TLSA record in DANE?

To sign a TLS server's public key Signup and view all the answers

What does the configuration option SSLStrictSNIVHostCheck do in Apache HTTPD?

Serves the virtual host only to clients that support SNI Signup and view all the answers

Which of the following is a characteristic of a Root CA certificate?

It is self-signed Signup and view all the answers

What is the purpose of HID in security?

To alert security personnel of potential security incidents Signup and view all the answers

What is the purpose of the command ulimit in Bash?

To set the maximum size of written files Signup and view all the answers

Which of the following is a best practice for implementing HID?

Configure HID to alert security personnel of potential security incidents Signup and view all the answers

What is the purpose of the chown command in Linux?

To set the owner and group of a file Signup and view all the answers

What is the purpose of Wireshark capture filters?

To capture only a specific type of network traffic Signup and view all the answers

What is the purpose of the command openvas-nvt-sync?

To update NVTs from the OpenVAS NVT feed Signup and view all the answers

What is the purpose of the execute permission bit in Linux?

To allow a file to be executed Signup and view all the answers

Which option of mount.cifs specifies the user that appears as the local owner of the files of a mounted CIFS share when the server does not provide ownership information?

uid Signup and view all the answers

Which of the following practices are important for the security of private keys?

Private keys should have a sufficient length for the algorithm used for key generation Signup and view all the answers

What is the purpose of NSEC3 in DNSSEC?

To prevent zone enumeration Signup and view all the answers

Which command is used to run a new shell for a user changing the SELinux context?

newrole Signup and view all the answers

Which file is used to configure AIDE?

/etc/aide/aide.conf Signup and view all the answers

What is the purpose of ndpmon?

It monitors the network for neighbor discovery messages from new IPv6 hosts and routers Signup and view all the answers

What is the advantage of creating private keys on the systems where they will be used?

They are more secure because they never leave the system Signup and view all the answers

What is the purpose of keeping private keys confidential?

To prevent unauthorized access to encrypted data Signup and view all the answers

What is the purpose of the `setfattr` command?

To set an extended attribute on a file in Linux Signup and view all the answers

What is an example of a behavioral-based HID technique?

Anomaly-based detection Signup and view all the answers

What is the difference between a SetUID and SetGID bit?

SetUID allows a file to be executed with the permissions of the file owner, while SetGID allows a file to be executed with the permissions of the group owner Signup and view all the answers

What is the purpose of the `auditd` tool?

To manage the Linux Audit system Signup and view all the answers

What is a buffer overflow?

A type of software vulnerability Signup and view all the answers

What is the purpose of the `ausearch` command?

To search and filter the audit log Signup and view all the answers

What package management tools can be used to verify the integrity of installed files on a Linux system?

RPM and DPKG Signup and view all the answers

What is a honeypot?

A decoy system intended to distract attackers Signup and view all the answers

What is the purpose of the `openssl` command with the `-servername` option?

To specify the host name to use for TLS Server Name Indication Signup and view all the answers

What is an asymmetric key?

A key used for both encryption and decryption that is generated in a pair Signup and view all the answers

What is the purpose of a honeypot?

To lure attackers into a trap Signup and view all the answers

Which of the following is used to perform DNSSEC validation on behalf of clients?

Recursive name server Signup and view all the answers

What is the purpose of IP sets?

To group together IP addresses referenced by netfilter rules Signup and view all the answers

What is the purpose of an extended attribute in Linux?

To store additional metadata about a file Signup and view all the answers

Which file is used to configure rkhunter?

/etc/rkhunter.conf Signup and view all the answers

What is the purpose of TSIG in DNS?

To sign DNS messages for secure communication Signup and view all the answers

What is privilege escalation?

An attack that exploits a vulnerability to gain elevated privileges Signup and view all the answers

What is the purpose of the pam_cracklib PAM module?

To check new passwords against dictionary words and enforce complexity Signup and view all the answers

What is the purpose of SELinux?

To implement mandatory access control Signup and view all the answers

What is the purpose of the openvpn command?

To establish a secure VPN connection Signup and view all the answers

What is the primary purpose of issuing and signing X.509 certificates?

To issue and sign digital certificates for secure communication Signup and view all the answers

What is the purpose of the push directive in an OpenVPN server configuration?

To send network configuration information to the client Signup and view all the answers

Which of the following is a valid stanza for a client configuration in FreeRADIUS?

client private-network-1 { ipaddr = 192.0.2.0/24 secret = testing123-1 } Signup and view all the answers

What is the purpose of the Linux Malware Detect tool?

To detect malware on a Linux system Signup and view all the answers

What is a Trojan?

A type of malware that disguises itself as legitimate software Signup and view all the answers

What is the purpose of the dnssec-keygen command?

To generate DNS keys Signup and view all the answers

What is the purpose of a trust anchor?

A root certificate that is trusted by a particular CA Signup and view all the answers

What is a rogue access point?

An unauthorized access point that is set up to look like a legitimate one Signup and view all the answers

What is the purpose of the chmod command in Linux?

To set the permissions of a file Signup and view all the answers

What is the main purpose of a Certificate Authority (CA)?

To issue digital certificates Signup and view all the answers

What is the primary purpose of an X.509 certificate?

To verify the identity of a website Signup and view all the answers

What is the main difference between a chroot environment and a regular environment?

Chroot environments are isolated and have limited access to resources Signup and view all the answers

Which of the following statements is true about AppArmor?

AppArmor is less complex and easier to configure than SELinux Signup and view all the answers

What is the primary purpose of AIDE?

To detect intrusions and system changes Signup and view all the answers

What is phishing?

A type of social engineering attack Signup and view all the answers

What is the primary purpose of DNS over TLS and DNS over HTTPS?

To provide secure communication between DNS clients and servers Signup and view all the answers

What is the primary purpose of a Certificate Revocation List (CRL)?

A list of X.509 certificates that have been revoked by a particular CA Signup and view all the answers

Which of the following DNS records is used to map an IP address to a hostname?

PTR Signup and view all the answers

What is host intrusion detection (HID)?

A system that monitors and detects potential security threats on a single computer or server Signup and view all the answers

What is the purpose of a DNSKEY record in DNSSEC?

To sign a DNS zone Signup and view all the answers

Which tool is used to check for rootkits on a Linux system?

chkrootkit Signup and view all the answers

What happens when the command getfattr afile is run while the file afile has no extended attributes set?

No output is produced and getfattr exits with a value of 0 Signup and view all the answers

Which command deletes only the first key from a LUKS device?

cryptsetup luksDelKey /dev/sda 1 1 Signup and view all the answers

Which statement is true regarding eCryptfs?

eCryptfs cannot be used to encrypt only directories that are the home directory of a regular Linux user Signup and view all the answers

Which command disables the automatic password expiry for a user?

chage --maxdays -1 usera Signup and view all the answers

How does TSIG authenticate name servers for secured zone transfers?

Both servers use a secret key that is shared between the servers Signup and view all the answers

Which of the following utilities is used to generate keys for DNSSEC?

dnssec-keygen Signup and view all the answers

Which command makes the contents of an eCryptfs encrypted directory available to the user?

ecryptfs-mount-private Signup and view all the answers

Which of the following is an example of an HID tool?

Security information and event management (SIEM) system Signup and view all the answers

Which statement is true regarding an X509 certificate?

This certificate belongs to a certification authority Signup and view all the answers

What is the primary function of rkhunter?

To detect rootkits and other security threats Signup and view all the answers

What is the purpose of a Certificate Authority (CA)?

To issue certificates to organizations Signup and view all the answers

What is a man-in-the-middle attack?

An attack that intercepts communications between two parties to steal information Signup and view all the answers

Which permission bit allows a user to delete a file?

Write Signup and view all the answers

What is a certificate chain?

A sequence of certificates used to verify the authenticity of a digital certificate Signup and view all the answers

Which command changes the source IP address to 192.0.2.11 for all IPv4 packets which go through the network interface eth0?

iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to-source 192.0.2.11 Signup and view all the answers

Which of the following commands adds users using SSSD’s local service?

ss_useradd Signup and view all the answers

Which DNS records are used in DNSSEC?

RRSIG Signup and view all the answers

What is the purpose of OpenVPN?

To create a virtual private network Signup and view all the answers

Which of the following scan techniques with nmap?

All of the above Signup and view all the answers

Which of the following authentication methods was added to NFS in version 4?

Kerberos authentication Signup and view all the answers

What is OCSP stapling?

A mechanism that allows a server to provide proof of the revocation status of its own SSL/TLS certificate Signup and view all the answers

What is the purpose of the command ipa-server-install?

To install and configure a new FreeIPA server, including all sub-components, and creates a new FreeIPA domain Signup and view all the answers

What is the openssl command to generate a certificate signing request (CSR) using the already existing private key contained in the file private/keypair.pem?

openssl req –new -key private/keypair.pem –out req/csr.pem Signup and view all the answers

What is Cryptography?

The art of sending secret messages Signup and view all the answers

What type of activity does HID monitor for?

Unauthorized access attempts Signup and view all the answers

What is a ciphertext?

The encrypted message Signup and view all the answers

Which of the following commands defines an audit rule that monitors read and write operations to the file /etc/firewall/rules and associates the rule with the name firewall?

auditctl –w /etc/firewall/rules –p rw –k firewall Signup and view all the answers

What is a rootkit?

A type of malware that disguises itself as legitimate software Signup and view all the answers

Which of the following commands displays all ebtable rules contained in the table filter including their packet and byte counters?

ebtables -t filter –L --Lc Signup and view all the answers

What is the purpose of a TLSA record in DANE?

To sign a TLS server's public key Signup and view all the answers

Which command is used to update NVTs from the OpenVAS NVT feed?

openvas-nvt-sync Signup and view all the answers

What is the purpose of the SSLVerifyClient require configuration option in Apache HTTPD?

To require a client certificate for authentication Signup and view all the answers

Which of the following statements are true regarding the certificate of a Root CA?

It is a self-signed certificate. Signup and view all the answers

Which of the following permissions is required to execute a file?

Execute Signup and view all the answers

How can host scans be automated on a Linux system?

Using cron Signup and view all the answers

Which of the following configuration options makes Apache HTTPD require a client certificate for authentication?

SSLVerifyClient require Signup and view all the answers

What is the purpose of SELinux permissions?

To provide additional access control Signup and view all the answers

Which command is used to set the owner and group of a file in Linux?

chown Signup and view all the answers

Which of the following Wireshark capture filters is valid?

portrange 10000/tcp-15000/tcp Signup and view all the answers

Study Notes

Security and Networking Concepts

Exam 303-300: LPIC-3 Security

File Systems and Permissions

File ownership in Linux systems restricts access to files only to their owner
chown command is used to change the ownership of a file
chmod command is used to set the permissions of a file
Extended attributes in Linux store additional metadata about a file
getfacl command is used to view the access control list of a file
setfacl command is used to set the access control list of a file

Network Security

DNSSEC (Domain Name System Security Extensions) is a security protocol for DNS
NSEC3 is a type of DNS record used in DNSSEC
RRSIG is a type of DNS record used in DNSSEC
TSIG is used to sign DNS messages for secure communication
IP sets group together IP addresses that can be referenced by netfilter rules

Cryptography and Certification

Asymmetric key: a key used for encryption and decryption that is generated in a pair
Symmetric key: a key used for encryption and decryption that is the same
Certificate Authority (CA) issues and signs X.509 certificates
Trust anchor: a root certificate that is trusted by a particular CA
TLSA record in DANE publishes X.509 certificate and certificate authority information in DNS

Linux Security

Linux Audit system detects intrusions and system changes
ausearch command is used to search and filter the audit log
auditd is the Linux Audit system's daemon
SELinux (Security-Enhanced Linux) is a Mandatory Access Control (MAC) system

Network Attacks and Defenses

Buffer overflow: a type of software vulnerability
Man-in-the-middle attack: an attack that intercepts communications between two parties
DoS (Denial of Service) attack: an attack that floods a network or server with traffic to make it unavailable
Trojan: a type of malware that disguises itself as legitimate software
Rogue access point: an unauthorized access point that is set up to look like a legitimate one

Firewalls and Networking

iptables command is used to configure the Linux firewall
nmap is a network exploration and security auditing tool
OpenVPN is a virtual private network (VPN) solution

Other Security Concepts

Privilege escalation: an attack that exploits a vulnerability to gain elevated privileges
Honeypot: a network security tool designed to lure attackers into a trap
AIDE (Advanced Intrusion Detection Environment) is a file integrity checker and incident response tool
rkhunter is a tool to detect rootkits and other security threats### Security Fundamentals
Host intrusion detection (HID) monitors a single computer or server for potential security threats.
HID can detect unauthorized access attempts, but does not provide automatic removal of detected threats.
Cryptography is the art of sending secret messages.

File Permissions and Access Control

SELinux permissions are verified before standard Linux permissions.
The chown command is used to set the owner and group of a file in Linux.
Access control lists (ACLs) in Linux specify fine-grained permissions for users and groups.

Network Security

OCSP stapling is a mechanism that allows a server to provide proof of the revocation status of its own SSL/TLS certificate.
LUKS (Linux Unified Key Setup) is a disk encryption system.
cryptsetup is used to set up and configure LUKS devices.
getfattr displays extended attributes of a file or directory.

Certificates and Authentication

X.509 certificates are digital documents that verify the identity of a website, person, device, or company.
A Certificate Revocation List (CRL) is a list of X.509 certificates that have been revoked by a particular CA.
DNSSEC (Domain Name System Security Extensions) is a set of extensions to DNS that provide security by verifying the authenticity of DNS data.
TSIG (Transaction Signature) authenticates name servers in order to perform secured zone transfers.
eCryptfs is a stacked Linux filesystem that provides encryption and access control for directories.

System Security

chage is used to change the password expiry information for a user.
snort-stat displays statistics from the running Snort process.
chkrootkit is a tool that checks for rootkits on a Linux system.
AppArmor and SELinux are both mandatory access control systems, but they have different implementation and configuration approaches.
aide is a tool that detects intrusions and system changes.

DNS Security

DNSSEC-signed zones use a key signing key to sign the zone signing key of the zone.
The DNSKEY record in DNSSEC is used to sign a DNS zone.
DNS over TLS and DNS over HTTPS provide secure communication between DNS clients and servers.
DANE (DNS-based Authentication of Named Entities) is used to secure HTTPS connections.

Other Security Concepts

Phishing is a type of social engineering attack that exploits human psychology to gain access to sensitive information.
Social engineering is a type of attack that exploits human psychology to gain access to sensitive information.
Rootkits are a type of malware that disguises itself as legitimate software.
openvas-nvt-sync is a command that updates NVTs (Network Vulnerability Tests) from the OpenVAS NVT feed.
ipa-server-install is a command that installs and configures a new FreeIPA server, including all sub-components, and creates a new FreeIPA domain.

Security and Networking Concepts

Exam 303-300: LPIC-3 Security

File Systems and Permissions

File ownership in Linux systems restricts access to files only to their owner
chown command is used to change the ownership of a file
chmod command is used to set the permissions of a file
Extended attributes in Linux store additional metadata about a file
getfacl command is used to view the access control list of a file
setfacl command is used to set the access control list of a file

Network Security

DNSSEC (Domain Name System Security Extensions) is a security protocol for DNS
NSEC3 is a type of DNS record used in DNSSEC
RRSIG is a type of DNS record used in DNSSEC
TSIG is used to sign DNS messages for secure communication
IP sets group together IP addresses that can be referenced by netfilter rules

Cryptography and Certification

Asymmetric key: a key used for encryption and decryption that is generated in a pair
Symmetric key: a key used for encryption and decryption that is the same
Certificate Authority (CA) issues and signs X.509 certificates
Trust anchor: a root certificate that is trusted by a particular CA
TLSA record in DANE publishes X.509 certificate and certificate authority information in DNS

Linux Security

Linux Audit system detects intrusions and system changes
ausearch command is used to search and filter the audit log
auditd is the Linux Audit system's daemon
SELinux (Security-Enhanced Linux) is a Mandatory Access Control (MAC) system

Network Attacks and Defenses

Buffer overflow: a type of software vulnerability
Man-in-the-middle attack: an attack that intercepts communications between two parties
DoS (Denial of Service) attack: an attack that floods a network or server with traffic to make it unavailable
Trojan: a type of malware that disguises itself as legitimate software
Rogue access point: an unauthorized access point that is set up to look like a legitimate one

Firewalls and Networking

iptables command is used to configure the Linux firewall
nmap is a network exploration and security auditing tool
OpenVPN is a virtual private network (VPN) solution

Other Security Concepts

Privilege escalation: an attack that exploits a vulnerability to gain elevated privileges
Honeypot: a network security tool designed to lure attackers into a trap
AIDE (Advanced Intrusion Detection Environment) is a file integrity checker and incident response tool
rkhunter is a tool to detect rootkits and other security threats### Security Fundamentals
Host intrusion detection (HID) monitors a single computer or server for potential security threats.
HID can detect unauthorized access attempts, but does not provide automatic removal of detected threats.
Cryptography is the art of sending secret messages.

File Permissions and Access Control

SELinux permissions are verified before standard Linux permissions.
The chown command is used to set the owner and group of a file in Linux.
Access control lists (ACLs) in Linux specify fine-grained permissions for users and groups.

Network Security

OCSP stapling is a mechanism that allows a server to provide proof of the revocation status of its own SSL/TLS certificate.
LUKS (Linux Unified Key Setup) is a disk encryption system.
cryptsetup is used to set up and configure LUKS devices.
getfattr displays extended attributes of a file or directory.

Certificates and Authentication

X.509 certificates are digital documents that verify the identity of a website, person, device, or company.
A Certificate Revocation List (CRL) is a list of X.509 certificates that have been revoked by a particular CA.
DNSSEC (Domain Name System Security Extensions) is a set of extensions to DNS that provide security by verifying the authenticity of DNS data.
TSIG (Transaction Signature) authenticates name servers in order to perform secured zone transfers.
eCryptfs is a stacked Linux filesystem that provides encryption and access control for directories.

System Security

chage is used to change the password expiry information for a user.
snort-stat displays statistics from the running Snort process.
chkrootkit is a tool that checks for rootkits on a Linux system.
AppArmor and SELinux are both mandatory access control systems, but they have different implementation and configuration approaches.
aide is a tool that detects intrusions and system changes.

DNS Security

DNSSEC-signed zones use a key signing key to sign the zone signing key of the zone.
The DNSKEY record in DNSSEC is used to sign a DNS zone.
DNS over TLS and DNS over HTTPS provide secure communication between DNS clients and servers.
DANE (DNS-based Authentication of Named Entities) is used to secure HTTPS connections.

Other Security Concepts

Phishing is a type of social engineering attack that exploits human psychology to gain access to sensitive information.
Social engineering is a type of attack that exploits human psychology to gain access to sensitive information.
Rootkits are a type of malware that disguises itself as legitimate software.
openvas-nvt-sync is a command that updates NVTs (Network Vulnerability Tests) from the OpenVAS NVT feed.
ipa-server-install is a command that installs and configures a new FreeIPA server, including all sub-components, and creates a new FreeIPA domain.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

IT Security and Linux System Administration Quiz

Questions and Answers

What is the purpose of the uid option in the mount.cifs command?

Which of the following is a good practice for private key security?

What is the main purpose of NSEC3 in DNSSEC?

What is the command used to change the SELinux context for a user?

Which file is used to configure the AIDE system?

What is the purpose of the ndpmon command?

Which of the following is a good practice for private key security?

What is the purpose of the mount.cifs command?

What is the purpose of rkhunter?

Which command is used to view the access control list of a file?

What is a man-in-the-middle attack?

Which permission bit allows a user to delete a file?

What is the purpose of a Certificate Authority (CA)?

Which command adds users using SSSD’s local service?

Which DNS records are used in DNSSEC?

Which of the following terms refer to existing scan techniques with nmap?

Which command changes the source IP address to 192.0.2.11 for all IPv4 packets which go through the network interface eth0?

Which of the following methods can be used to deactivate a rule in Snort?

What is the primary function of the tool that reads syslog files containing Snort information?

Which command is used to delete the first key from a LUKS device?

What is a characteristic of eCryptfs?

How does TSIG authenticate name servers for secured zone transfers?

Which of the following is NOT a component of FreeIPA?

What is the purpose of the dnssec-keygen utility?

What type of system is a Security Information and Event Management (SIEM) system?

What information is contained in an X509 certificate?

What command is used to make the contents of an eCryptfs encrypted directory available to the user?

What is the purpose of the chage command?

What does a network link monitor do?

What is an asymmetric key used for?

What is an example of a behavioral-based HID technique?

What command revokes ACL-based write access for groups and named users on a file?

What is the purpose of the setfattr command?

What is a buffer overflow?

What tool can be used to manage the Linux Audit system?

What is the main difference between a DNSSEC-signed zone and a non-DNSSEC-signed zone?

What is the difference between a SetUID and SetGID bit?

What is a honeypot?

What is the primary purpose of a Certificate Revocation List (CRL)?

What package management tools can be used to verify the integrity of installed files on a Linux system?

What is the main benefit of using AppArmor over SELinux?

What is the primary purpose of a DNSKEY record in DNSSEC?

What is the main difference between a chroot environment and a regular environment?

What is the primary purpose of AIDE?

What is phishing?

What is the primary purpose of DNS over TLS and DNS over HTTPS?

What is the main difference between AppArmor and SELinux?

What is the primary purpose of an X.509 certificate?

What is the purpose of the Linux Audit system?

What is the purpose of file ownership in Linux systems?

What is a Trojan?

What is the purpose of a trust anchor?

Which of the following is used to issue and sign X.509 certificates?

What is the purpose of the command dnssec-keygen?

What is a rogue access point?

What is the purpose of the push directive in an OpenVPN server configuration?

What is Linux Malware Detect?

What is a DoS attack?

What is the primary purpose of a honey pot in network security?

Which type of DNS server is responsible for performing DNSSEC validation on behalf of clients?

What is the purpose of the ipa trust-add command in FreeIPA?

What is the purpose of the ntop command with the --set-admin-password option?

What is a symmetric key in cryptography?

What is the purpose of the pam_cracklib PAM module?

What is the purpose of TSIG in DNS?

What is the purpose of IP sets in Linux?

What is the purpose of an extended attribute in Linux?

What is the effect of the iptables command with the -A INPUT option?

What is the purpose of OCSP stapling?

What is the main purpose of HID?

What is a ciphertext?

What is the command to install and configure a new FreeIPA server?

What is Cryptography?

What is the purpose of the ebtables command?

What is a rootkit?

What is the purpose of the openssl command?

What is the protocol commonly used to transmit X.509 certificates?

What is a plaintext?

What is the purpose of the `uid` option in the `mount.cifs` command?

What is the purpose of the `ndpmon` command?

What is the purpose of the `mount.cifs` command?

What is the purpose of the `setfattr` command?

What is the purpose of the `auditd` tool?

What is the purpose of the `ausearch` command?

What is the purpose of the `openssl` command with the `-servername` option?