Protect Your GitHub Actions with Semgrep

The comprehensive exploration highlights the potential security vulnerabilities associated with GitHub Actions (GHA), focusing on risks such as shell injection attacks, compromised runners, and the misuse of the pull_request_target trigger. The post underscores the dangers of stolen secrets and unauthorized repository modifications when a GHA runner is compromised, emphasizing how attackers can exploit the GITHUB_TOKEN and other authentication methods. It discusses the importance of treating GitHub context data as untrusted, suggests using environment variables to mitigate shell injection vulnerabilities, and warns against using deprecated commands enabled by the ACTIONS_ALLOW_UNSECURE_COMMANDS variable. The piece advocates for vigilant use of the pull_request_target trigger, careful auditing of third-party actions, and the employment of tools like Semgrep to detect vulnerabilities. Additionally, it provides insights into GITHUB_TOKEN permissions, offering strategies to safeguard against potential exploits in the complex GHA ecosystem.