CVE-2023-37942 in Monitor Job Type Plugin
Summary
by MITRE • 07/12/2023
Jenkins External Monitor Job Type Plugin 206.v9a_94ff0b_4a_10 and earlier does not configure its XML parser to prevent XML external entity (XXE) attacks.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/02/2023
The Jenkins External Monitor Job Type Plugin vulnerability represents a critical security flaw that exposes systems to XML external entity attacks, commonly known as XXE exploits. This vulnerability affects versions 206.v9a_94ff0b_4a_10 and earlier of the plugin, which is widely used for monitoring external systems and services within Jenkins environments. The flaw stems from insufficient configuration of the XML parser component, which fails to disable external entity resolution and other dangerous XML processing features that attackers can leverage to execute malicious payloads.
The technical implementation of this vulnerability occurs when the plugin processes XML data without proper security restrictions on the underlying XML parser. Attackers can craft malicious XML payloads that include external entity declarations, allowing them to access local files, perform server-side request forgery attacks, or potentially execute arbitrary code depending on the Jenkins environment configuration. The vulnerability specifically relates to the plugin's failure to set secure parser properties such as disallowing external entities, disabling DTD processing, and restricting access to network resources during XML parsing operations. This misconfiguration creates an attack surface where unauthenticated users can manipulate XML input to extract sensitive data or perform unauthorized operations.
The operational impact of this vulnerability extends beyond simple data exposure, as it can enable attackers to escalate privileges within the Jenkins environment. An attacker who successfully exploits this XXE vulnerability could gain access to sensitive configuration files, credentials stored in Jenkins, or even system files that contain authentication tokens and other critical information. The attack vector typically involves submitting specially crafted XML content through the plugin's monitoring functionality, which then gets parsed by the vulnerable XML parser. This vulnerability is particularly dangerous in enterprise environments where Jenkins serves as a central automation platform, as it could provide attackers with a foothold to compromise the entire CI/CD pipeline infrastructure.
Organizations should immediately update to the patched version of the Jenkins External Monitor Job Type Plugin to mitigate this vulnerability. The remediation process involves upgrading to a version that properly configures the XML parser to disable external entity resolution and other dangerous XML processing features. Security teams should also implement network segmentation and access controls to limit exposure, while monitoring for suspicious XML processing activities in Jenkins logs. Additionally, organizations should conduct comprehensive vulnerability assessments to identify other plugins or components that might be susceptible to similar XXE vulnerabilities. This vulnerability aligns with CWE-611 (Improper Restriction of XML External Entity Reference) and represents a common pattern in web application security where XML parsers are not properly secured against external entity processing attacks. The ATT&CK framework categorizes this as a technique for exploitation through insecure XML processing, which can lead to privilege escalation and data exfiltration in Jenkins environments.