Privilege escalation in Step-Security Harden-Runner
CVE-2025-32955
Harden-Runner is a CI/CD security agent that works like an EDR for GitHub Actions runners. Versions from 0.12.0 to before 2.12.0 are vulnerable to `disable-sudo` bypass. Harden-Runner includes a policy option `disable-sudo` to prevent the GitHub Actions runner user from using sudo. This is implemented by removing the runner user from the sudoers file. However, this control can be bypassed as the runner user, being part of the docker group, can interact with the Docker daemon to launch privileged containers or access the host filesystem. This allows the attacker to regain root access or restore the sudoers file, effectively bypassing the restriction. This issue has been patched in version 2.12.0.
EPSS: 0.002 (11.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.0 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H.
Affected products
- Step-security Harden-runner — versions >= 0.12.0, < 2.12.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-32955?
- CVE-2025-32955 is a medium-severity vulnerability in Step-Security Harden-Runner, classified under Privilege Chaining. CVSS score: 6.0/10. Published 2025-04-21.
- How severe is CVE-2025-32955?
- Medium severity. CVSS v3 base score is 6.0 out of 10.