CVE-2021-39913 in Community Edition
Summary
by MITRE • 11/05/2021
Accidental logging of system root password in the migration log in all versions of GitLab CE/EE before 14.2.6, all versions starting from 14.3 before 14.3.4, and all versions starting from 14.4 before 14.4.1 allows an attacker with local file system access to obtain system root-level privileges
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Analysis
by VulDB Data Team • 06/12/2026
The vulnerability identified as CVE-2021-39913 represents a critical security flaw in GitLab Community Edition and Enterprise Edition versions where system root passwords are inadvertently logged during migration processes. This issue stems from improper handling of sensitive credentials within the application's logging mechanisms, creating a scenario where privileged system information becomes accessible through log files that are typically maintained for operational troubleshooting and monitoring purposes. The flaw exists in the migration workflow where the system performs database schema updates and configuration changes, inadvertently capturing and persisting root credentials in plaintext within log output files.
This vulnerability directly maps to CWE-209, which addresses improper error handling that reveals sensitive information, and CWE-312, which covers the exposure of sensitive information through log files. The technical implementation flaw occurs when GitLab's migration scripts execute commands that require root privileges, but the system fails to sanitize or redact sensitive credential information before writing to log files. The logging mechanism does not properly distinguish between operational messages and credential data, resulting in the persistence of root passwords in migration logs that may be accessible to any user with local file system access to the GitLab installation directory.
The operational impact of this vulnerability is severe and far-reaching, as it provides attackers with a direct pathway to obtain system root-level privileges without requiring additional attack vectors or exploitation techniques. An attacker with local file system access to a GitLab server can simply navigate to the migration log files and extract the root password, subsequently gaining complete control over the system. This creates a privilege escalation scenario that bypasses traditional authentication mechanisms and potentially allows for persistent access, lateral movement within the network, and data exfiltration. The vulnerability is particularly dangerous in environments where GitLab servers are hosted on shared infrastructure or where local access controls are insufficiently enforced.
The attack surface for this vulnerability is broad and includes any environment where GitLab is installed with local file system access permissions, particularly affecting organizations with less stringent access controls or those that maintain multiple administrators with local access to GitLab servers. Mitigation strategies should include immediate implementation of log file access controls, ensuring that migration logs are not stored in locations accessible to non-privileged users, and implementing proper credential sanitization during migration processes. Organizations should also consider implementing automated log monitoring and alerting systems to detect unauthorized access to sensitive log files, along with regular security audits to identify and remediate similar credential exposure issues. The recommended solution involves patching the affected GitLab versions to properly sanitize logging output and implementing principle of least privilege for file system access to migration-related directories. Additionally, security teams should establish procedures for reviewing log file contents periodically to identify and remove any sensitive information that may have been inadvertently logged.