ONLYOFFICE Docs Server Path Traversal Vulnerability

CVE-2021-3199 is a path traversal vulnerability in ONLYOFFICE Docs Server that can be exploited when JWT authentication is in use. The vulnerability is triggered via a '/.. sequence' in an image upload parameter, potentially allowing remote code execution. The flaw affects the ONLYOFFICE DocumentServer and was patched in version 5.6.3. As an open-source component, it may also affect third-party products or libraries that incorporate ONLYOFFICE. CISA has listed this vulnerability in its Known Exploited Vulnerabilities catalog, assigning it a high criticality rating. Organizations using ONLYOFFICE Docs are urged to apply security updates as prioritized under BOD 26-04. Forensics triage requirements may apply for affected federal agencies.