Description

Missing permission checks in Jenkins XebiaLabs XL Deploy Plugin 26.1.0 and earlier allow attackers with Overall/Read permission to enumerate credentials IDs of credentials stored in Jenkins.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.4",
  "pubDate": "2026-09-02T16:17:32.033Z",
  "pubdate": "2026-09-02T16:17:32.033Z",
  "executiveSummary": "The Jenkins XebiaLabs XL Deploy Plugin is susceptible to an information disclosure vulnerability due to insufficient permission validation within its API endpoints. This flaw allows attackers possessing only 'Overall/Read' permissions to enumerate the identifiers of credentials stored within the Jenkins instance. The vulnerability affects versions 26.1.0 and earlier. By exploiting this issue, unauthorized users can gain visibility into the internal configuration of credentials, facilitating further targeted attacks. The risk implication is significant as credential enumeration serves as a critical reconnaissance step for credential harvesting or hijacking attempts. Exploitation requires minimal privileges, specifically standard 'Overall/Read' access, which is commonly granted to authenticated users in many Jenkins environments, thereby expanding the potential attack surface. No interaction from administrative users is required to perform the enumeration, posing a risk to the confidentiality of the Jenkins security configuration.",
  "technicalDetails": "The root cause of this vulnerability lies in the improper implementation of access control checks within the Jenkins XebiaLabs XL Deploy Plugin's web-exposed methods. Specifically, the plugin fails to enforce proper authorization constraints when processing requests that retrieve credential information. In Jenkins, credentials management typically requires higher-privileged access, such as 'Credentials/View' or 'Jenkins/Administer' permissions, depending on the configuration. However, the affected plugin components erroneously permit users with only 'Overall/Read' access to invoke functions intended for restricted use.\nThe exploitation mechanism involves an attacker sending crafted HTTP requests to the vulnerable plugin endpoints. Because the plugin does not validate whether the requesting user possesses the necessary credentials-level permissions, the backend logic proceeds to serialize and return the list of credential IDs stored within the Jenkins credentials provider associated with the plugin. This bypass of security constraints effectively elevates the privileges of an 'Overall/Read' user, granting them unauthorized access to metadata that should be protected.\nThe attack flow proceeds as follows: First, an authenticated attacker with 'Overall/Read' permissions identifies the API endpoints associated with the XebiaLabs XL Deploy Plugin. Second, the attacker issues a GET or POST request to the specific method responsible for fetching available credentials for configuration tasks. Third, due to the missing permission check, the server-side code executes the request without verifying if the user is authorized to view credentials. Finally, the plugin responds with a structured object containing the identifiers of all available credentials, allowing the attacker to map out sensitive integration points, such as deployment targets, cloud provider accounts, or API tokens.\nThe vulnerable component is the credential lookup mechanism within the plugin's integration logic. Since this vulnerability relies on the plugin's own API exposure, it is reachable via the network through the standard Jenkins web interface. The impact is primarily categorized as information disclosure; however, the ability to enumerate credential IDs provides an attacker with a roadmap for identifying which systems are integrated with the Jenkins server, significantly lowering the complexity of subsequent credential exploitation or phishing attacks targeting the identified services."
}