GHSA-r8g4-86fx-92mq

Summary

The isValidMedia() function in src/media/parse.ts allows arbitrary file paths including absolute paths, home directory paths, and directory traversal sequences. An agent can read any file on the system by outputting MEDIA:/path/to/file, exfiltrating sensitive data to the user/channel.

Details

Location: src/media/parse.ts:17-27

The path validation accepts dangerous patterns:

function isValidMedia(candidate: string, opts?: { allowSpaces?: boolean }) {
  if (candidate.startsWith("/")) return true;      // ALLOWS /etc/passwd
  if (candidate.startsWith("./")) return true;
  if (candidate.startsWith("../")) return true;    // ALLOWS ../../etc/passwd
  if (candidate.startsWith("~")) return true;      // ALLOWS ~/secrets
  return false;
}

No validation ensures the path is within a safe directory or is actually a media file.

PoC

Agent outputs any of:

MEDIA:/etc/passwd
MEDIA:~/.ssh/id_rsa
MEDIA:~/.aws/credentials
MEDIA:../../../etc/passwd

The file contents are rendered/sent to the requesting user or channel.

Impact

• Read ANY file accessible to the agent user
• Exfiltrate SSH keys (~/.ssh/id_rsa)
• Steal cloud credentials (~/.aws/credentials)
• Access API keys (.env, config.json)
• Read system files (/etc/passwd, /etc/shadow)

Note: PR #4930 contains a fix but is NOT MERGED - production is vulnerable.