CVE-2024-52587 in harden-runner
Summary
by MITRE • 11/19/2024
StepSecurity's Harden-Runner provides network egress filtering and runtime security for GitHub-hosted and self-hosted runners. Versions of step-security/harden-runner prior to v2.10.2 contain multiple command injection weaknesses via environment variables that could potentially be exploited under specific conditions. However, due to the current execution order of pre-steps in GitHub Actions and the placement of harden-runner as the first step in a job, the likelihood of exploitation is low as the Harden-Runner action reads the environment variable during the pre-step stage. There are no known exploits at this time. Version 2.10.2 contains a patch.
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Analysis
by VulDB Data Team • 11/19/2024
The vulnerability identified as CVE-2024-52587 affects StepSecurity's Harden-Runner, a security tool designed to provide network egress filtering and runtime security for GitHub-hosted and self-hosted runners. This tool operates as a critical component in securing automated workflows by controlling outbound network connections and monitoring execution environments. The affected versions prior to v2.10.2 contain command injection weaknesses that can be triggered through manipulation of environment variables, representing a significant security risk in continuous integration and deployment pipelines where such tools are commonly employed.
The technical flaw manifests as multiple command injection vulnerabilities that can be exploited when environment variables are improperly handled within the Harden-Runner execution context. These weaknesses allow attackers to inject malicious commands that could be executed within the runner environment, potentially leading to unauthorized access, data exfiltration, or system compromise. The vulnerability specifically occurs when the tool processes environment variables during its pre-step execution phase, where input validation and sanitization are insufficient to prevent malicious payload injection. This type of vulnerability aligns with CWE-77 and CWE-78 categories, which specifically address command injection flaws in software systems.
The operational impact of this vulnerability extends beyond simple security concerns to potentially affect the integrity of entire CI/CD pipelines. When exploited, these command injection weaknesses could allow attackers to execute arbitrary code on runner systems, potentially gaining access to sensitive build artifacts, credentials, or source code repositories. The risk is particularly concerning in environments where Harden-Runner is deployed as the first step in GitHub Actions jobs, as this positioning provides early access to the execution environment. However, the current execution order in GitHub Actions where pre-steps are processed before the main workflow steps creates a natural defense mechanism that reduces exploitation likelihood, though it does not eliminate the risk entirely.
The security implications of CVE-2024-52587 are significant within the context of modern DevOps practices, where GitHub Actions and similar platforms are extensively used for automated testing and deployment. The vulnerability demonstrates the importance of proper input validation and sanitization in security tools, particularly those that operate in privileged execution environments. Organizations using Harden-Runner should consider the ATT&CK framework's T1059.001 technique for command and script injection when assessing their security posture, as this vulnerability directly relates to the exploitation of such techniques in automated environments. The patch included in version 2.10.2 addresses these command injection weaknesses through improved environment variable handling and input validation mechanisms. Organizations should prioritize updating to the patched version to eliminate the risk of exploitation, particularly in environments where runner systems may be exposed to untrusted inputs or where the tool is used in high-value CI/CD pipelines. The vulnerability serves as a reminder of the critical need for security considerations in automation tools and the potential for seemingly benign security controls to become attack vectors when input handling is inadequate.