CVE-2021-21249

CVE-2021-21249 describes a post-authentication remote code execution vulnerability in OneDev, an all-in-one DevOps platform, affecting versions prior to 4.0.3. This flaw stems from insecure YAML parsing using SnakeYaml, which allows the instantiation of arbitrary classes, enabling attackers to execute arbitrary code. With a CVSS score of 8.8 (HIGH), this vulnerability has a network attack vector, low attack complexity, and high impacts on confidentiality, integrity, and availability. While there is no evidence of active exploitation or public exploit code (Metasploit, Nuclei, ExploitDB), the vulnerability has garnered significant community discussion with 10 mentions, indicating awareness among security researchers.