CVE-2021-21244 in OneDev
Summary
by MITRE • 01/16/2021
OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, There is a vulnerability that enabled pre-auth server side template injection via Bean validation message tampering. Full details in the reference GHSA. This issue was fixed in 4.0.3 by disabling validation interpolation completely.
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Analysis
by VulDB Data Team • 02/15/2021
The vulnerability identified as CVE-2021-21244 affects OneDev, an all-in-one DevOps platform that provides integrated solutions for software development lifecycle management. This platform serves organizations requiring comprehensive continuous integration, continuous delivery, and project management capabilities. The security flaw represents a critical pre-authentication server-side template injection vulnerability that could potentially allow attackers to execute arbitrary code on affected systems. The vulnerability specifically targets the Bean validation message handling mechanism within the platform's validation framework, creating an avenue for remote code execution without requiring valid authentication credentials.
The technical flaw stems from improper handling of validation messages within the Bean validation framework used by OneDev. When the platform processes validation messages, it fails to properly sanitize or escape user-supplied input that gets incorporated into validation error messages. This allows an attacker to manipulate validation messages in a way that triggers template injection vulnerabilities. The vulnerability operates through the validation interpolation mechanism, where user-controllable data gets processed through template engines without adequate sanitization. This represents a classic server-side template injection vulnerability that falls under CWE-74, which specifically addresses Improper Neutralization of Special Elements in Output Used by a Downstream Component. The flaw exists because the platform's validation system allows arbitrary data to be interpolated into error messages without proper input validation or sanitization, creating a direct path for template injection attacks.
The operational impact of this vulnerability is severe and far-reaching for organizations using affected versions of OneDev. Attackers could exploit this vulnerability to execute arbitrary code on the server, potentially leading to complete system compromise, data exfiltration, and persistence within the target environment. The pre-authentication nature of the vulnerability means that no valid credentials are required to exploit the flaw, making it particularly dangerous as it can be leveraged by anyone with access to the platform. Organizations relying on OneDev for their DevOps operations face significant risk of unauthorized access to their development environments, source code repositories, and CI/CD pipelines. The vulnerability could enable attackers to gain access to sensitive development credentials, production deployment configurations, and potentially escalate privileges to compromise underlying infrastructure. This represents a critical threat to software development security and could lead to supply chain attacks if exploited against development environments that handle sensitive applications.
The fix implemented in OneDev version 4.0.3 addresses the root cause by completely disabling validation interpolation, which effectively eliminates the attack vector. This remediation approach aligns with security best practices for preventing template injection vulnerabilities by removing the problematic functionality entirely rather than attempting to patch the sanitization mechanism. Organizations should immediately upgrade to version 4.0.3 or later to protect against this vulnerability. The mitigation strategy also includes monitoring for suspicious validation-related activities and implementing network-level controls to restrict access to the OneDev platform where possible. This vulnerability demonstrates the importance of proper input validation and the dangers of template interpolation in server-side applications, aligning with ATT&CK technique T1211 for lateral movement through exploitation of server-side template injection vulnerabilities. Organizations should conduct thorough security assessments of their DevOps platforms and review all validation message handling mechanisms to ensure similar vulnerabilities are not present in other systems.