CVE-2021-21247 : Vulnerability Insights and Analysis
Learn about CVE-2021-21247, a critical post-auth unsafe deserialization vulnerability in OneDev BasePage before 4.0.3, enabling potential remote code execution. Ensure immediate mitigation and long-term security measures.
OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, a vulnerability exists in the application's BasePage allowing for Unsafe Deserialization, leading to potential post-auth Remote Code Execution (RCE) attacks. The issue has been assigned a CVSS base score of 9.6, indicating critical severity.
Understanding CVE-2021-21247
This CVE pertains to a security vulnerability in OneDev, a devops platform, which could be exploited for post-auth RCE if not patched.
What is CVE-2021-21247?
CVE-2021-21247 refers to the post-auth unsafe deserialization vulnerability on the BasePage of OneDev before version 4.0.3, potentially allowing attackers to execute arbitrary code post-authentication.
The Impact of CVE-2021-21247
The vulnerability could lead to high confidentiality and integrity impact, with a low complexity attack vector over the network. Successful exploitation could result in significant consequences.
Technical Details of CVE-2021-21247
The vulnerability stems from BasePage's registration of an AJAX event listener that decodes and deserializes the 'data' query parameter, accessible via a POST request to any page other than the login page.
Vulnerability Description
The flaw enables attackers to exploit the deserialization process, potentially leading to remote code execution post-authentication.
Affected Systems and Versions
The issue affects OneDev versions prior to 4.0.3, exposing systems running these versions to the security risk.
Exploitation Mechanism
By submitting a crafted POST request to any page other than the login page, threat actors can access the AJAX event listener and potentially execute unauthorized commands.
Mitigation and Prevention
It is crucial to apply immediate mitigation steps and long-term security practices to protect against CVE-2021-21247.
Immediate Steps to Take
Users are advised to update OneDev to version 4.0.3 or later to mitigate the vulnerability. Additionally, monitoring for any signs of exploit attempts is recommended.
Long-Term Security Practices
Incorporating secure coding practices, regular security audits, and ensuring timely system updates can help prevent similar vulnerabilities in the future.
Patching and Updates
Regularly applying patches and updates provided by the vendor is essential to ensure the security of OneDev and protect against known vulnerabilities.