A path traversal flaw exists in the upload handler of OpenBMB ChatDev that can be exploited by any remote user without authentication. The flaw allows an attacker to supply a specially crafted multipart filename containing path traversal sequences or an absolute path to the upload endpoint. The server then constructs a destination path without sanitization, enabling the attacker to write or delete any file on the system that the application process can access. Depending on the target file, this can lead to further compromise, such as injection of malicious binaries or alteration of critical configuration files, potentially enabling remote code execution, data loss, or service disruption.

OpenBMB ChatDev versions 2.2.0 and earlier are affected. The vulnerability was fixed in commit 4fd4da603801766b14ad8788649cfc1ad21f99a6, which applies to all later releases. Users running the unpatched 2.2.0 series should review their build and apply the fix or upgrade beyond 2.2.0.

The CVSS score of 8.8 indicates high severity, while the EPSS score is not available. The vulnerability is not listed in CISA’s KEV catalog. Attackers can exploit the flaw remotely by sending a crafted upload request to the POST uploads session endpoint; no credentials are required. If file permissions permit, the attacker can overwrite system files or deploy malware. The risk is therefore significant and the exploit is straightforward for an unauthenticated remote attacker.