CVE-2020-2242 in Database Plugin
Summary
by MITRE
A missing permission check in Jenkins database Plugin 1.6 and earlier allows attackers with Overall/Read access to Jenkins to connect to an attacker-specified database server using attacker-specified credentials.
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Analysis
by VulDB Data Team • 11/12/2020
The vulnerability described in CVE-2020-2242 represents a critical authorization bypass flaw within the Jenkins database plugin version 1.6 and earlier. This issue stems from a missing permission check that allows authenticated users with only Overall/Read access to establish database connections to arbitrary database servers using credentials specified by the attacker. The flaw fundamentally undermines the principle of least privilege by enabling read-only users to potentially access sensitive database resources beyond their intended permissions. The vulnerability exists within the plugin's database connection handling mechanism where proper access controls fail to validate whether the user possesses appropriate authorization levels for the requested database operations.
From a technical perspective, this vulnerability operates at the permission validation layer where Jenkins fails to properly verify user credentials against the required authorization levels before establishing database connections. The missing permission check creates a path where an attacker can leverage their existing Overall/Read access to manipulate database connection parameters and credentials, effectively bypassing the normal access controls that should restrict database operations. This flaw is particularly dangerous because it allows attackers to connect to any database server specified by the attacker, potentially leading to unauthorized data access, exfiltration, or even database manipulation depending on the target system's configuration. The vulnerability can be exploited through the Jenkins web interface or API endpoints that handle database connection requests, making it accessible to attackers who have minimal access to the Jenkins instance but can still leverage the compromised plugin functionality.
The operational impact of CVE-2020-2242 extends beyond simple unauthorized database access, creating potential for significant data breaches and system compromise. Attackers can use this vulnerability to connect to internal databases that may contain sensitive information such as user credentials, personal data, financial records, or proprietary business information. The ability to specify arbitrary database servers and credentials means that attackers can target not only the Jenkins instance's own database but potentially access connected systems within the organization's network infrastructure. This vulnerability directly relates to CWE-284 which addresses improper access control, and can be mapped to ATT&CK technique T1078 which covers valid accounts and privilege escalation. Organizations using Jenkins with database plugins are particularly vulnerable if they have multiple database connections configured or if their Jenkins instance is accessible to users with read-only access but not properly restricted from database operations.
Mitigation strategies for this vulnerability require immediate action including upgrading the Jenkins database plugin to version 1.7 or later where the permission check has been properly implemented. Organizations should also implement network segmentation to limit access to database servers from Jenkins instances and enforce strict firewall rules that restrict outbound database connections. Additional security measures include reviewing and tightening user access controls within Jenkins, ensuring that users with Overall/Read access cannot perform database connection operations, and implementing monitoring for unusual database connection patterns. The fix implemented in the newer plugin versions addresses the core issue by enforcing proper permission validation before allowing database connection establishment. Security teams should also consider implementing database activity monitoring and alerting mechanisms to detect unauthorized database access attempts, as well as conducting regular security assessments of Jenkins plugins to identify similar permission bypass vulnerabilities. Organizations should review their Jenkins configurations to ensure that database plugin functionality is appropriately restricted and that users cannot leverage read-only access to perform potentially dangerous database operations.