threat-modeling.md

Threat Model Analysis for jenkinsci/jenkins

Threat: Vulnerable Plugin Exploitation

Description: Attacker exploits known vulnerabilities in installed Jenkins plugins. This can be done by targeting publicly disclosed vulnerabilities or through automated vulnerability scanners. Exploitation can range from Cross-Site Scripting (XSS) to Remote Code Execution (RCE).

Impact: Depending on the vulnerability, impacts can range from data theft, unauthorized access to Jenkins, to complete compromise of the Jenkins master and agents. RCE vulnerabilities can lead to full system takeover.

Affected Jenkins Component: Jenkins Plugins

Risk Severity: High to Critical (depending on the vulnerability)

Mitigation Strategies:

• Regularly update Jenkins core and all installed plugins to the latest versions.
• Implement a plugin update policy and schedule.
• Use a plugin vulnerability scanner to identify vulnerable plugins.
• Only install necessary plugins from trusted sources (Jenkins Plugin Manager).
• Consider using a plugin approval process before installing new plugins.
• Monitor plugin security advisories and announcements.

Threat: Malicious Plugin Installation

Description: Attacker tricks administrators into installing a malicious plugin. This could be achieved through social engineering, typosquatting plugin names, or compromising plugin update sites. Malicious plugins can contain backdoors, data exfiltration mechanisms, or code to disrupt CI/CD processes.

Impact: Complete compromise of the Jenkins server, data theft (including credentials and source code), supply chain attacks by injecting malicious code into builds, and disruption of CI/CD pipelines.

Affected Jenkins Component: Jenkins Plugins, Plugin Manager

Risk Severity: Critical

Mitigation Strategies:

• Only install plugins from the official Jenkins Plugin Manager or verified, trusted sources.
• Implement a plugin approval process requiring security review before installation.
• Verify plugin publisher and reputation before installation.
• Monitor network traffic for unusual outbound connections after plugin installations.
• Use security scanning tools to analyze plugin code for suspicious activity (if feasible).

Threat: Jenkins Core Vulnerability Exploitation

Description: Attacker exploits vulnerabilities in the Jenkins core application itself. This could be through publicly disclosed vulnerabilities or zero-day exploits. Exploitation can lead to various attacks, including authentication bypass, arbitrary code execution, and information disclosure.

Impact: Complete compromise of the Jenkins master, data breaches, disruption of CI/CD pipelines, and potential downstream supply chain attacks.

Affected Jenkins Component: Jenkins Core

Risk Severity: Critical

Mitigation Strategies:

• Regularly update Jenkins core to the latest stable version.
• Subscribe to Jenkins security mailing lists and advisories.
• Implement a robust patching process for Jenkins core.
• Harden the Jenkins server operating system and network configuration.
• Use a Web Application Firewall (WAF) to protect Jenkins from common web attacks.

Threat: Deserialization Vulnerability Exploitation

Description: Attacker exploits deserialization vulnerabilities in Jenkins' Java remoting protocol. This is often achieved by sending specially crafted serialized Java objects to the Jenkins master or agents. Successful exploitation can lead to Remote Code Execution (RCE).

Impact: Remote code execution on the Jenkins master or agents, potentially leading to full system compromise and data breaches.

Affected Jenkins Component: Jenkins Remoting, Java Serialization

Risk Severity: Critical

Mitigation Strategies:

• Keep Jenkins core and agents updated to versions with deserialization vulnerability fixes.
• Disable or restrict access to JNLP agents if possible, favoring more secure agent connection methods (e.g., SSH).
• Implement network segmentation to limit the impact of agent compromise.
• Monitor for suspicious network traffic related to Java serialization.

Threat: Compromised Agent Takeover

Description: Attacker compromises a Jenkins agent machine. This could be through vulnerabilities in services running on the agent, weak credentials, or malware. Once compromised, the attacker can use the agent to attack the Jenkins master or inject malicious code into builds.

Impact: Agent takeover, potential master compromise, data theft from the agent environment, and injection of malicious code into builds executed on the agent, potentially leading to supply chain attacks.

Affected Jenkins Component: Jenkins Agents

Risk Severity: High

Mitigation Strategies:

• Harden agent machines: apply security patches, disable unnecessary services, and use strong passwords.
• Implement network segmentation to isolate agents from sensitive networks.
• Use secure agent connection methods (e.g., SSH, HTTPS).
• Regularly monitor agent machines for suspicious activity.
• Use ephemeral agents (e.g., container-based agents) to reduce the attack surface.

Threat: Unauthorized Agent Registration

Description: Attacker registers an unauthorized agent to the Jenkins master. This could be due to weak agent registration security or misconfiguration. A rogue agent can be used to execute malicious code on the master or inject backdoors into builds.

Impact: Rogue agents could be used to steal data, inject malicious code into builds, disrupt the CI/CD pipeline, or potentially compromise the Jenkins master.

Affected Jenkins Component: Jenkins Agent Registration, Master-Agent Communication

Risk Severity: High

Mitigation Strategies:

• Implement strong agent authorization and authentication mechanisms.
• Use agent access control lists to restrict which agents can connect.
• Regularly review and audit registered agents.
• Monitor agent registration attempts for suspicious activity.
• Use agent connection secrets and verify agent identities.

Threat: Weak or Default Credentials

Description: Attacker gains access to Jenkins using default or weak administrator credentials. This is a common attack vector for publicly exposed Jenkins instances.

Impact: Unauthorized access to Jenkins, allowing attackers to modify configurations, access sensitive data, and disrupt CI/CD pipelines.

Affected Jenkins Component: Jenkins Authentication, User Management

Risk Severity: Critical

Mitigation Strategies:

• Change default administrator credentials immediately upon installation.
• Enforce strong password policies for all Jenkins users.
• Implement multi-factor authentication (MFA) for administrator accounts.
• Regularly audit user accounts and permissions.
• Consider using Single Sign-On (SSO) for centralized authentication.

Threat: Unsecured Script Console Access

Description: Attacker gains access to the Jenkins Script Console, which allows execution of arbitrary Groovy code on the Jenkins master. This can happen due to misconfiguration or insufficient access control.

Impact: Remote code execution on the Jenkins master, complete system compromise, and potential data breaches.

Affected Jenkins Component: Jenkins Script Console

Risk Severity: Critical

Mitigation Strategies:

• Restrict access to the Script Console to only highly trusted administrators.
• Implement strong authentication and authorization for Script Console access.
• Audit Script Console usage and log all executed commands.
• Consider disabling the Script Console entirely if not absolutely necessary.

Threat: Insecure Job Configurations

Description: Jobs are configured to execute arbitrary code from untrusted sources or with insufficient input validation. This can be exploited by attackers to inject malicious code into builds.

Impact: Code injection vulnerabilities, arbitrary command execution on agents or the master, and potential data breaches.

Affected Jenkins Component: Jenkins Job Configuration, Pipeline Scripts

Risk Severity: High

Mitigation Strategies:

• Sanitize and validate all user inputs in job configurations and pipeline scripts.
• Avoid executing arbitrary code from untrusted sources within jobs.
• Use parameterized builds carefully and validate parameters.
• Implement code review for job configurations and pipeline scripts.
• Apply security linters and static analysis tools to pipeline code.

Threat: Lack of Security Updates and Patching

Description: Failing to regularly update Jenkins core and plugins leaves known vulnerabilities unpatched, making the system vulnerable to exploitation.

Impact: Increased risk of exploitation of known vulnerabilities, leading to system compromise and data breaches.

Affected Jenkins Component: Jenkins Core, Jenkins Plugins, Update Center

Risk Severity: High to Critical

Mitigation Strategies:

• Implement a regular patching schedule for Jenkins core and plugins.
• Automate the patching process where possible.
• Monitor security advisories and announcements for Jenkins and plugins.
• Prioritize patching critical and high severity vulnerabilities.
• Test patches in a non-production environment before applying them to production.

Threat: Pipeline Script Vulnerabilities

Description: Vulnerabilities in pipeline scripts (Groovy code) can be exploited by attackers. This includes code injection, insecure use of libraries, and exposed credentials within the pipeline code.

Impact: Arbitrary code execution within the pipeline context, potential access to credentials and sensitive data, and disruption of the CI/CD pipeline.

Affected Jenkins Component: Jenkins Pipelines, Groovy Scripting Engine

Risk Severity: High

Mitigation Strategies:

• Implement secure coding practices for pipeline scripts.
• Sanitize and validate all inputs used in pipeline scripts.
• Avoid using dynamic code execution (e.g., evaluate) with untrusted input.
• Use credential management plugins to securely handle credentials in pipelines.
• Implement code review and static analysis for pipeline scripts.

Threat: Insecure Pipeline Libraries

Description: Using shared pipeline libraries that contain vulnerabilities or malicious code. This can introduce vulnerabilities into all pipelines that use the library.

Impact: Introduction of vulnerabilities into all pipelines using the library, potential for supply chain attacks within the organization, and widespread compromise of CI/CD processes.

Affected Jenkins Component: Jenkins Shared Libraries, Pipeline Execution

Risk Severity: High

Mitigation Strategies:

• Implement a review and approval process for shared pipeline libraries.
• Scan shared libraries for vulnerabilities using static analysis and dependency scanning tools.
• Control access to shared library repositories and restrict modifications.
• Regularly update and patch shared libraries.
• Use version control and code signing for shared libraries to ensure integrity.

Threat: Pipeline Code Tampering

Description: Unauthorized modification of pipeline code in source control or within Jenkins itself. This can be done to inject malicious code into builds or disrupt the CI/CD pipeline.

Impact: Injection of malicious code into builds, disruption of CI/CD pipelines, and potential for supply chain attacks.

Affected Jenkins Component: Jenkins Pipeline Definition, Source Code Management (SCM) Integration

Risk Severity: High

Mitigation Strategies:

• Protect pipeline code repositories with strong access controls and authentication.
• Implement code review and version control for pipeline code changes.
• Use branch protection and pull request workflows for pipeline code modifications.
• Audit pipeline code changes and access logs.
• Consider using immutable pipeline definitions to prevent unauthorized modifications within Jenkins.