CVE-2024-21623 in OTCLient
Summary
by MITRE • 01/02/2024
OTCLient is an alternative tibia client for otserv. Prior to commit db560de0b56476c87a2f967466407939196dd254, the /mehah/otclient "`Analysis - SonarCloud`" workflow is vulnerable to an expression injection in Actions, allowing an attacker to run commands remotely on the runner, leak secrets, and alter the repository using this workflow. Commit db560de0b56476c87a2f967466407939196dd254 contains a fix for this issue.
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Analysis
by VulDB Data Team • 01/03/2024
CVE-2024-21623 represents a critical command injection vulnerability within the OTClient project's GitHub Actions workflow, specifically affecting the `/mehah/otclient` repository. This vulnerability stems from improper input validation within the Actions configuration, creating a path for remote code execution that directly impacts the CI/CD infrastructure. The flaw exists in the workflow's handling of user-provided inputs, where malicious actors can manipulate variables to inject arbitrary commands that execute within the runner environment. This type of vulnerability aligns with CWE-74, which describes improper neutralization of special elements used in a command, and CWE-94, covering improper control of generation of code. The security implications extend beyond simple command execution as the vulnerability allows for secret leakage, repository alteration, and complete compromise of the automated build environment.
The technical exploitation of this vulnerability occurs through the GitHub Actions workflow configuration where user inputs are directly incorporated into shell commands without proper sanitization or validation. Attackers can craft malicious inputs that, when processed by the workflow, result in unintended command execution on the runner system. The vulnerability's impact is amplified by the elevated privileges typically granted to CI/CD runners, which often have access to repository secrets, deployment credentials, and write permissions to the codebase. This scenario creates a perfect storm for supply chain attacks where an attacker can not only execute arbitrary code but also exfiltrate sensitive information and modify the source code itself, potentially introducing backdoors or other malicious modifications that persist through future builds.
The operational consequences of this vulnerability are severe for any organization relying on GitHub Actions for their CI/CD pipelines, particularly those using OTClient or similar projects. The vulnerability enables attackers to gain persistent access to the build environment, potentially leading to data breaches, code tampering, and unauthorized deployments. Organizations may face reputational damage, regulatory compliance violations, and financial losses due to compromised build systems. The vulnerability also represents a significant risk to downstream consumers of the affected software, as any compromised builds could propagate malicious code to end users. This attack vector falls under the ATT&CK framework's T1059.001 technique for command and scripting interpreter, specifically shell scripting, and T1566.001 for spearphishing via social media, as the vulnerability may be exploited through compromised workflows or malicious pull requests.
Mitigation strategies should focus on implementing proper input validation and sanitization within GitHub Actions workflows, avoiding direct command construction from user inputs. Organizations should adopt the principle of least privilege for CI/CD runners, restricting access to only necessary resources and secrets. The fix implemented in commit db560de0b56476c87a2f967466407939196dd254 likely involved proper escaping of inputs, use of parameterized commands, or complete redesign of the vulnerable workflow logic. Regular security auditing of CI/CD configurations, implementation of secret scanning, and monitoring for unusual workflow activities should be standard practices. Additionally, organizations should consider implementing code signing, dependency verification, and multi-factor authentication for repository access to further reduce the attack surface and prevent exploitation of similar vulnerabilities in the future.