Description Preview
The Jenkins Filesystem Trigger Plugin version 0.40 and earlier contains a vulnerability where its XML parser is not properly configured to prevent XML external entity (XXE) attacks. This misconfiguration allows attackers to potentially extract sensitive information from the server hosting Jenkins, execute server-side request forgery (SSRF) attacks, or cause denial of service conditions through the processing of malicious XML input.
Overview
The Filesystem Trigger Plugin for Jenkins enables builds to be triggered based on filesystem changes. The vulnerability exists because the plugin does not properly disable external entity processing in its XML parser. When parsing XML input, the plugin may process external entities referenced in the XML document, which can lead to:
- Disclosure of confidential files on the Jenkins server
- Server-side request forgery (SSRF)
- Denial of service through resource exhaustion
- Potential remote code execution in specific environments
This vulnerability is particularly concerning in environments where the Jenkins instance has access to sensitive internal resources or where it runs with elevated privileges.
Remediation
To address this vulnerability, users should take the following actions:
- Update the Jenkins Filesystem Trigger Plugin to version newer than 0.40 which contains the security fix
- If immediate updating is not possible, consider temporarily disabling the plugin until it can be updated
- Implement additional network security controls to limit the Jenkins server's ability to make outbound connections
- Review Jenkins logs for any suspicious activity that might indicate exploitation attempts
- Ensure Jenkins is running with the principle of least privilege to minimize potential impact
References
- Jenkins Security Advisory (2021-05-25): https://www.jenkins.io/security/advisory/2021-05-25/#SECURITY-2339
- OSS Security Mailing List Discussion: http://www.openwall.com/lists/oss-security/2021/05/25/3
- OWASP XML External Entity Prevention Cheat Sheet: https://cheatsheetseries.owasp.org/cheatsheets/XML_External_Entity_Prevention_Cheat_Sheet.html
- Jenkins Filesystem Trigger Plugin documentation: https://plugins.jenkins.io/fstrigger/
Industry ExposureMost to leastThis section illustrates the prevalence of a specific Common Vulnerabilities and Exposures (CVE) across various industries based on customer reports. The ranking displays industries from the most to least affected by this particular vulnerability, offering valuable insight into where this CVE has been most frequently observed. This information can help organizations within these sectors prioritize their security efforts, understand their relative risk exposure compared to their peers, and focus remediation strategies where they are most needed. By understanding the industry-specific impact, organizations can make more informed decisions regarding patching, resource allocation, and overall risk management related to this CVE.
This section illustrates the prevalence of a specific Common Vulnerabilities and Exposures (CVE) across various industries based on customer reports. The ranking displays industries from the most to least affected by this particular vulnerability, offering valuable insight into where this CVE has been most frequently observed. This information can help organizations within these sectors prioritize their security efforts, understand their relative risk exposure compared to their peers, and focus remediation strategies where they are most needed. By understanding the industry-specific impact, organizations can make more informed decisions regarding patching, resource allocation, and overall risk management related to this CVE.
- Accommodation & Food ServicesAccommodation & Food Services
- Administrative, Support, Waste Management & Remediation ServicesAdministrative, Support, Waste Management & Remediation Services
- Agriculture, Forestry Fishing & HuntingAgriculture, Forestry Fishing & Hunting
- Arts, Entertainment & RecreationArts, Entertainment & Recreation
- ConstructionConstruction
- Educational ServicesEducational Services
- Finance and InsuranceFinance and Insurance
- Health Care & Social AssistanceHealth Care & Social Assistance
- InformationInformation
- Management of Companies & EnterprisesManagement of Companies & Enterprises
- ManufacturingManufacturing
- MiningMining
- Other Services (except Public Administration)Other Services (except Public Administration)
- Professional, Scientific, & Technical ServicesProfessional, Scientific, & Technical Services
- Public AdministrationPublic Administration
- Real Estate Rental & LeasingReal Estate Rental & Leasing
- Retail TradeRetail Trade
- Transportation & WarehousingTransportation & Warehousing
- UtilitiesUtilities
- Wholesale TradeWholesale Trade
