Description

Jenkins Script Security Plugin 1412.v7737b_3405f86 and earlier does not enforce a permission check in the method that controls the "Force the use of the sandbox globally in the system" setting, allowing attackers to disable it through Stapler data binding.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.3",
  "pubDate": "2026-09-02T16:17:30.563Z",
  "pubdate": "2026-09-02T16:17:30.563Z",
  "executiveSummary": "The Jenkins Script Security Plugin, in versions 1412.v7737b_3405f86 and earlier, contains a critical security vulnerability involving the improper enforcement of access controls. This vulnerability allows an attacker to manipulate the global 'Force the use of the sandbox' configuration setting through Stapler data binding.\nBy bypassing the mandatory permission check, an unauthorized actor can disable the global sandbox enforcement mechanism. The sandbox is a primary security feature in Jenkins designed to restrict the execution of potentially malicious scripts by limiting access to sensitive Java APIs and system resources. Successful exploitation grants an attacker the ability to execute arbitrary code with the privileges of the Jenkins controller, effectively leading to full system compromise.\nThe attack requires no special authentication to the plugin configuration page itself, as the underlying Stapler data binding mechanism allows for unauthorized state modification. This risk is significant for Jenkins instances that rely on the sandbox to isolate build processes and script execution. Organizations using affected versions are highly susceptible to remote code execution (RCE) attacks originating from untrusted pipeline scripts or malicious users with existing low-privileged access to the Jenkins environment.",
  "technicalDetails": "The vulnerability resides within the Jenkins Script Security Plugin's configuration handling logic. Specifically, the method responsible for toggling the 'Force the use of the sandbox globally in the system' setting fails to perform the requisite authorization check (Jenkins.ADMINISTER) before processing state updates provided via Stapler data binding.\nStapler is the web framework utilized by Jenkins to map HTTP requests to Java object methods. Data binding occurs when Stapler automatically populates object fields based on request parameters. In this instance, the plugin exposes a setter method or a configuration object member that, when accessed via a specially crafted HTTP request, allows an attacker to bind a value of 'false' to the global sandbox enforcement variable.\nThe exploitation flow is as follows: An attacker crafts a malicious HTTP POST request targeting the configuration endpoint exposed by the plugin. Because the server-side logic fails to validate the initiator's permissions, the Stapler framework proceeds to update the internal configuration object. The application then persists this change to the global Jenkins configuration file (typically config.xml). Once the sandbox enforcement is disabled, any subsequent scripts submitted to the Jenkins environment—even those previously restricted by the sandbox—are executed without security constraints.\nUnder normal circumstances, the sandbox prevents unauthorized scripts from invoking dangerous methods, such as those related to file system access, network socket communication, or reflection-based exploitation. By disabling this global flag, the attacker removes these constraints, allowing the execution of arbitrary Groovy code that interacts directly with the Jenkins controller JVM. This post-exploitation state provides a direct pathway to complete control over the Jenkins controller, including the ability to exfiltrate credentials, modify build artifacts, or pivot into the underlying infrastructure hosting the Jenkins master instance.\nThe root cause is a deficiency in the access control layer within the plugin's controller logic, where the administrative requirement is omitted for a sensitive configuration modification method. This bypass occurs independently of the UI layer, as the Stapler binding mechanism operates at the request-processing level, rendering standard UI-based permission enforcement ineffective if the backend method is not explicitly secured."
}