Learn about CVE-2021-21243, a critical vulnerability in OneDev devops platform before 4.0.3. Understand the impact, technical details, and mitigation steps for Pre-Auth Unsafe Deserialization on KubernetesResource.
OneDev, an all-in-one devops platform, before version 4.0.3, has a vulnerability in a Kubernetes REST endpoint that exposes two methods allowing the deserialization of untrusted data without authentication checks. This issue, identified as CVE-2021-21243, could result in pre-auth remote code execution (RCE).
Understanding CVE-2021-21243
This vulnerability, named Pre-Auth Unsafe Deserialization on KubernetesResource, has a CVSS v3.1 base score of 10, indicating a critical severity level.
What is CVE-2021-21243?
In OneDev versions prior to 4.0.3, the vulnerable Kubernetes REST endpoint could be exploited to execute remote code without authentication, posing a serious security risk.
The Impact of CVE-2021-21243
The vulnerability could lead to high impacts on confidentiality and integrity, with the potential for attackers to achieve pre-auth RCE without requiring any privileges.
Technical Details of CVE-2021-21243
The vulnerability arises from the insecure deserialization of untrusted data on the KubernetesResource endpoint.
Vulnerability Description
Two methods exposed by the Kubernetes REST endpoint in OneDev prior to version 4.0.3 allow unauthenticated deserialization of data from the request body, enabling potential pre-auth RCE attacks.
Affected Systems and Versions
OneDev versions earlier than 4.0.3 are impacted by this vulnerability, exposing them to the risk of unauthorized code execution.
Exploitation Mechanism
Attackers can exploit the lack of authentication and authorization checks on the Kubernetes REST endpoint to send malicious requests with untrusted data, potentially leading to RCE.
Mitigation and Prevention
To address CVE-2021-21243, immediate steps should be taken to secure impacted systems and prevent potential exploitation.
Immediate Steps to Take
Upgrade OneDev to version 4.0.3 or higher to ensure the fix for this vulnerability is applied and the deserialization issue is resolved.
Long-Term Security Practices
Implement strong authentication and authorization mechanisms, conduct regular security audits, and stay informed about software updates and security patches to prevent similar vulnerabilities.
Patching and Updates
Regularly monitor for security advisories and apply patches promptly to mitigate the risk of exploitation.