CVE-2021-21690 is a critical vulnerability that allows agent processes in Jenkins to bypass file path filtering. This affects Jenkins versions 2.318 and earlier, including LTS versions 2.303.2 and earlier. With a CVSS score of 9.8, this vulnerability poses a significant threat to organizations using Jenkins for continuous integration and deployment.
The critical severity of this vulnerability is due to its potential impact on confidentiality, integrity, and availability. Attackers may leverage this vulnerability to perform unauthorized file operations, leading to severe exploits. Therefore, organizations should prioritize patching this vulnerability immediately.
As of now, there are no public exploits available, and it has not been included in the Known Exploited Vulnerabilities (KEV) catalog. However, the risk to organizations remains high, and immediate attention is required to mitigate potential impacts.
Organizations using vulnerable versions of Jenkins should assess their exposure and implement the necessary updates as soon as possible.
Vulnerability Details
The vulnerability described in CVE-2021-21690 allows agent processes to completely bypass file path filtering by wrapping file operations in an agent file path. This behavior was identified in Jenkins versions 2.318 and earlier, as well as LTS versions 2.303.2 and earlier. The severity of this vulnerability is classified as critical due to its high CVSS score of 9.8.
The attack vector is network-based with low complexity, requiring no privileges or user interaction. The vulnerability falls under the CWE classification CWE-22, indicating improper limitation of a pathname to a restricted directory.
For organizations using Jenkins, it is essential to apply the latest patches to mitigate this vulnerability. The publication date of this vulnerability was November 4, 2021, and it is crucial to remain vigilant against any potential exploits.
Technical Analysis
The root cause of CVE-2021-21690 stems from the failure of Jenkins to adequately enforce file path filtering for operations executed by agent processes. By wrapping file operations in an agent file path, attackers can bypass security restrictions typically enforced by the Jenkins system.
The attack vector is network-based, allowing attackers to exploit this vulnerability remotely. The complexity of the attack is low, as no special privileges are required, and user interaction is not necessary. The impact on confidentiality, integrity, and availability is categorized as high, indicating that successful exploitation could lead to significant data breaches or service disruptions.
Risk & Impact Analysis
Risk to organizations includes unauthorized access to sensitive files and potential manipulation of critical data. The blast radius of this vulnerability is substantial, as it affects all users of Jenkins versions 2.318 and earlier. Organizations utilizing Jenkins for deployment pipelines should assess their risk exposure and take immediate action to update their systems.
Given the critical CVSS score and the potential for exploitation, organizations should adopt a high urgency assessment for remediation. Immediate actions should be taken to patch affected systems to prevent unauthorized access.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of Jenkins include all versions prior to 2.319, specifically Jenkins 2.318 and earlier, and LTS versions 2.303.2 and earlier. Organizations should ensure they upgrade to the latest version to mitigate this vulnerability.
Mitigation & Remediation
To mitigate CVE-2021-21690, organizations must apply the latest patches provided by Jenkins. The recommended version to upgrade to is 2.319 or later. If an immediate upgrade is not possible, organizations should implement configuration hardening by restricting access to sensitive file paths and closely monitoring file operations.
For further details on Jenkins security practices, organizations can refer to the comprehensive guidance available through application security assessment resources.
Detection Guidance
Organizations should monitor logs for any unusual file operations initiated by Jenkins agents. Behavioral anomalies related to file access patterns can indicate potential exploitation of this vulnerability. Additionally, network signatures should be established to detect unauthorized access attempts.
AppSecure Threat Intelligence Insight
CVE-2021-21690 highlights a critical vulnerability that underscores the importance of secure configuration in automated environments. This vulnerability is a reminder for security teams to regularly review and update their security policies. As Jenkins is widely used in DevOps practices, the implications of this vulnerability extend beyond individual organizations.
The vulnerability represents a trend where automated systems may be susceptible to misconfigurations that lead to significant security risks. Organizations should be proactive in addressing such vulnerabilities and consider implementing a robust penetration testing methodology to identify potential weaknesses in their deployment pipelines.
This incident serves as a strategic defensive takeaway for organizations, emphasizing the need for continual security assessments and timely updates to maintain a secure environment.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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