CVE-2017-1000086 in Jenkins
Summary
by MITRE
The Periodic Backup Plugin did not perform any permission checks, allowing any user with Overall/Read access to change its settings, trigger backups, restore backups, download backups, and also delete all previous backups via log rotation. Additionally, the plugin was not requiring requests to its API be sent via POST, thereby opening itself to Cross-Site Request Forgery attacks.
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Analysis
by VulDB Data Team • 01/15/2021
The Periodic Backup Plugin vulnerability represents a critical authorization and authentication flaw that undermines the security posture of Jenkins environments. This vulnerability stems from the plugin's complete absence of permission validation mechanisms, creating a dangerous access control weakness that allows unauthorized users to perform administrative operations within the backup system. The flaw specifically affects the Jenkins continuous integration platform where the plugin is designed to manage automated backup operations for the system configuration, build artifacts, and other critical data elements. The vulnerability exists at the core of the plugin's architecture where it fails to implement proper access control checks, enabling any user with basic read permissions to escalate their privileges and execute operations typically restricted to administrators.
The technical implementation of this vulnerability manifests through multiple attack vectors that collectively compromise the integrity and availability of backup operations. The plugin's API endpoints lack proper POST request validation, which creates an inherent Cross-Site Request Forgery vulnerability that allows attackers to manipulate backup configurations through malicious web requests. This weakness enables attackers to trigger unauthorized backup operations, modify backup schedules, delete existing backup archives, and potentially restore malicious configurations from previous backup points. The absence of proper authentication checks means that users who should only have read access can perform destructive actions including complete backup deletion via log rotation mechanisms, effectively compromising the system's disaster recovery capabilities. The vulnerability directly maps to CWE-284, which addresses improper access control issues, and specifically demonstrates weaknesses in authorization enforcement and API security implementation.
The operational impact of this vulnerability extends far beyond simple privilege escalation, creating significant risks for organizations relying on Jenkins for their CI/CD pipelines and automated build processes. Attackers with minimal access levels can disrupt backup operations and potentially compromise system integrity by deleting backup archives, making the system vulnerable to data loss during actual emergencies. The ability to trigger unauthorized backups and restore from malicious backup points creates a sophisticated attack vector for persistent threats that could maintain access through compromised backup configurations. Organizations may experience complete loss of backup data, system downtime, and potential data corruption when attackers exploit these vulnerabilities. The impact is particularly severe in regulated environments where backup integrity and availability are mandated by compliance frameworks such as SOC 2, ISO 27001, and HIPAA requirements, as this vulnerability could lead to audit failures and regulatory penalties.
Mitigation strategies for this vulnerability require immediate implementation of access control restrictions and API security enhancements. Organizations should immediately disable or remove the vulnerable plugin from Jenkins instances until proper security patches are applied, though this may require careful planning to avoid disrupting existing backup operations. The recommended approach involves implementing proper authentication checks at all API endpoints, enforcing POST method validation for all administrative operations, and ensuring that backup operations require explicit administrative privileges. Security teams should also implement network-level access controls to restrict direct access to Jenkins backup endpoints and consider implementing additional monitoring for backup-related activities. The vulnerability demonstrates the critical importance of proper input validation and authentication enforcement, aligning with ATT&CK technique T1484.1 which addresses privilege escalation through access token manipulation. Organizations should also implement regular security assessments of Jenkins plugins to identify similar authorization weaknesses and ensure that all administrative operations require appropriate authorization levels.