CVE-2022-25209

Vulnerability

The Jenkins Chef Sinatra Plugin, versions 1.20 and earlier, does not configure its XML parser to disable XML external entity (XXE) processing. This is a classic XML External Entity (XXE) vulnerability, meaning the parser will resolve external entities defined in the XML document, potentially including references to local files or network resources. The vulnerability is present in all versions up to and including 1.20. [1] [2]

Exploitation

An attacker needs to be able to supply a crafted XML payload to the plugin's XML parsing endpoint. The exact attack vector is not detailed in the references, but typical XXE exploitation requires the ability to include a malicious XML document in a request processed by the vulnerable parser. No authentication or special privileges are mentioned as prerequisites; the vulnerability is in the default XML parsing configuration. [1]

Impact

Successful exploitation of the XXE vulnerability could allow an attacker to read arbitrary files on the Jenkins controller file system, perform server-side request forgery (SSRF) to internal networks, or cause a denial of service. The specific impact depends on the plugin's integration and whether the XML parser is used to handle external data. The advisory lists this issue as a high severity security vulnerability. [1] [2]

Mitigation

Jenkins has released security advisory 2022-02-15 addressing this vulnerability. Fixed versions of the Chef Sinatra Plugin are not explicitly listed in the provided references; however, users should upgrade to the latest version of the plugin as soon as it becomes available. As a general mitigation, administrators should review XML parser configurations in all Jenkins plugins and ensure external entity processing is disabled. No workaround is provided in the references. [1]