CVE-2019-15741 in Omnibus
Summary
by MITRE
An issue was discovered in GitLab Omnibus 7.4 through 12.2.1. An unsafe interaction with logrotate could result in a privilege escalation
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Analysis
by VulDB Data Team • 06/29/2024
The vulnerability identified as CVE-2019-15741 represents a critical privilege escalation flaw within GitLab Omnibus installations spanning versions 7.4 through 12.2.1. This issue stems from an insecure interaction between GitLab's logging infrastructure and the system's logrotate utility, creating a pathway for unauthorized users to elevate their privileges within the affected environment. The flaw specifically targets the manner in which GitLab handles log rotation processes, particularly when executing commands or scripts that manage log file permissions and ownership. This vulnerability operates at the intersection of system-level privilege management and application-level logging mechanisms, making it particularly dangerous in environments where GitLab serves as a central repository management system.
The technical implementation of this vulnerability involves a race condition or improper privilege handling during logrotate operations where GitLab's automated processes fail to properly validate or sanitize the execution context of log rotation commands. When logrotate is invoked by the system or GitLab itself, the vulnerable code path allows for potential manipulation of file permissions or execution of arbitrary commands with elevated privileges. This typically occurs when GitLab's logging subsystem creates or modifies log files in a manner that doesn't properly isolate the execution context from the system's root or administrative privileges. The flaw can be exploited by attackers who have access to the system, potentially through user accounts or compromised services, to gain root access or administrative privileges within the GitLab environment.
The operational impact of CVE-2019-15741 extends beyond simple privilege escalation, as it can lead to complete system compromise when exploited in conjunction with other vulnerabilities or attack vectors. Organizations running affected GitLab Omnibus versions face significant risk of unauthorized access to source code repositories, user data, and system resources. The vulnerability can be particularly devastating in development environments where GitLab serves as the primary code repository and CI/CD pipeline management system. Attackers could potentially access sensitive source code, modify or delete repository contents, compromise continuous integration processes, or establish persistent access to the system. This makes the vulnerability particularly attractive to threat actors targeting software development environments, as it provides a pathway to access not just the GitLab instance but potentially the entire underlying infrastructure.
Mitigation strategies for CVE-2019-15741 focus primarily on upgrading to patched versions of GitLab Omnibus where the logrotate interaction has been properly secured. Organizations should immediately update to GitLab versions 12.3.0 or later, which contain fixes addressing the privilege escalation vulnerability. Additionally, system administrators should review and harden the logrotate configuration files to ensure that GitLab's logging processes execute with minimal required privileges. This includes implementing proper file ownership and permission controls, disabling unnecessary log rotation features, and monitoring logrotate processes for unauthorized modifications. The fix typically involves proper privilege separation during log rotation operations and ensuring that any scripts or commands executed during log rotation maintain appropriate security boundaries. Security teams should also implement monitoring solutions to detect anomalous logrotate behavior or unauthorized privilege escalation attempts, aligning with defense-in-depth principles and reducing the attack surface for similar vulnerabilities. This vulnerability aligns with CWE-276, which addresses improper privilege management, and maps to ATT&CK technique T1068, which covers privilege escalation through local exploits.