Authentication and Unix Users

A user account with the highest privileges, allowing access to modify any file and impersonate any other user.

A system in which users provide their password to authenticate, and the system verifies it by comparing the provided password with a hashed version stored in a file.

A network-based authentication system where user information is centrally stored, allowing users to access any machine on the network with a single login.

A challenge-response protocol used for authentication, where a server sends a challenge and the user responds with calculated keys derived from their password hash.

The vulnerability created when an attacker gains access to the root account, enabling them to modify system files and impersonate any user, potentially compromising the entire system.

An attack where an attacker steals the password hash instead of the actual password, making it useless to store the hash.

A protocol that uses hashes to securely authenticate users on a network.

A protocol used for authentication on Windows networks, often used alongside Kerberos.

A system that allows different programs to use a centralized authentication system, making it easier to manage user access across multiple applications.

The PAM activity that verifies a user's identity, often through password authentication but can also use other methods.

A process of deciding if an entity is allowed to access a resource.

A software mechanism used for controlling access to system resources, like hardware, files, or network connections.

A software mechanism used for controlling access to system resources like hardware, files, or network connections.

A structured mechanism used to control user logins, based on user-specific information.

A set of instructions used by the operating system to manage processes, including creation, termination, loading, execution, and waiting.

A set of instructions used by the operating system to manage files, including creation, deletion, opening, closing, reading, and writing.

A set of instructions used by the operating system to manage devices, including requesting, releasing, reading, and writing.

A temporary workspace for a user session. It allows for resource allocation, including mounted directories, CPU and memory usage limits, and shell access.

The core set of software running in kernel space, with root permissions, responsible for protecting the system's integrity and enforcing security policies.

Modules that extend the kernel's functionality, loaded at runtime, and typically used for device drivers.

A file system that presents every system resource (hardware, processes) as a file to the operating system, enabling a consistent approach for interacting with them.

An integer index used by the kernel to track open files and resources, allowing the system to access and manage them efficiently.

The process of controlling access to system resources by defining who can perform what actions on specific files, sockets, and other objects.

A security mechanism that restricts the actions a process can perform based on its security context, preventing unauthorized access to sensitive data.

The set of permissions associated with a file or resource in a Unix system, controlling read, write, and execute access for different users and groups.

The process of ensuring the integrity and authenticity of software by verifying the origin and content of code before execution.

Using the same tools and APIs across different resources, offering a consistent and unified approach to managing the system.

A security concern where a child process inherits open file descriptors from its parent, potentially allowing it to access sensitive data that it should not have access to.

The process of checking permissions on a file or resource before granting access to a process that requests it.

The standard input stream, typically used for reading data entered by the user through the keyboard.

The standard output stream, typically used for writing data to the console, such as displaying output from commands.

The standard error stream, used for displaying error messages and diagnostic information.

A type of malware that spreads by infecting other files, typically executable files or office files with macros.

A standalone program that spreads without needing a host file, often through user interaction like emails or vulnerabilities in software.

Malware disguised as a useful program with hidden malicious functions, often used for stealing data or controlling infected devices.

Malware designed to hide its presence on a compromised system by modifying system files, processes, or creating hidden storage areas.

A damage routine is the action a malware performs after being activated. It can involve stealing data, encrypting files, or disrupting network access.

A malware that encrypts the data on a user's system and demands a ransom for its decryption.

A type of malware used to steal sensitive information from a user's system, often including passwords, bank details, or personal data.

Malware that explicitly targets specific users or organizations, often with highly specialized damage routines.

Malware that directly destroys or corrupts data on a computer, often for malicious purposes.

A technique where incoming files are screened for malware before being stored on the computer.

A method of detecting malware by analyzing patterns in files to see if they match known malicious signatures.

A technique used by malware to evade detection by signature-based methods. It creates many variations of the same malware, making it harder to identify.

A tool used by malware to compress and obfuscate its code, making it difficult to analyze and detect.

A technique that analyzes the behavior of a program to detect malicious activity, often by running it in a controlled environment.

Software designed to detect and remove malware from a system, often using both signature-based and behavior-based techniques.

A principle in the Biba model that prevents a subject from reading data with a lower integrity level than its own. It helps ensure that information with a higher integrity level isn't corrupted by access from lower integrity sources.

A principle in the Biba model that prevents a subject from writing data to an object with a higher integrity level than its own. This helps maintain the integrity of high-level data by preventing accidental or malicious modification.

A framework in the Linux kernel that allows different security models to be implemented without favoring any specific one. It works by introducing hooks for security-related operations.

A security mechanism used by the Linux kernel where every object, like processes, files, and sockets, has a security context or label. Access control is governed by rules that specify what actions are allowed based on these labels.

A method of isolating processes within a subdirectory of the filesystem. The isolated process cannot access files outside of that subdirectory.

A technique where an operating system provides multiple isolated user-space instances (containers, virtual environments, etc.) that share the host OS's kernel. It offers a layer of isolation with reduced overhead.

A method of running an entire computer system in software, allowing unmodified guest operating systems to run on a host platform. This involves translating the guest OS's instructions to the host's architecture.

A type of virtualization where hardware is emulated in software, allowing the execution of guest operating systems on a different architecture.

A type of virtualization where the guest operating system and drivers are modified to work with the virtualization layer. This achieves better performance by replacing non-VM-friendly instructions with calls to the hypervisor.

A virtualization technique where the hypervisor runs in a special, privileged ring (-1) in the hardware, providing better performance and security isolation than software-based approaches.

A type of OS-level virtualization that runs multiple, isolated Linux systems within a single host. Containers share the host kernel and offer a similar but more flexible approach than chroot jails.

A mechanism in Linux Containers (LXC) that restricts what a container can see and interact with. By providing a different view of global resources, namespaces isolate processes.

A mechanism in Linux Containers (LXC) that provides resource management for containers. It allows setting limits and managing resource sharing for groups of containers.

A middleware layer in Android that runs the Dalvik Virtual Machine, providing an abstraction layer between applications and the Linux kernel. It also provides core libraries and API for applications.

A security model in Android that isolates applications within sandboxes, controlling resource access and applying permissions to limit their capabilities.