Sign In
Advisories

Jan Local API Server CORS Origin Reflection via 0.0.0.0 Binding

Go Back
severity
medium
date
Affecting

  • Jan <= 0.8.4, fixed in commit 3e1c1e7

CWE
  • CWE-183 Permissive List of Allowed Inputs
  • CWE-942 Permissive Cross-domain Security Policy with Untrusted Domains
CVSS
5.3
CVSS V4 Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
Credit
George Chen
Description
Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.

Ready to get Started?

Explore VulnCheck, a next-generation Cyber Threat Intelligence platform, which provides exploit and vulnerability intelligence to help you prioritize and remediate vulnerabilities that matter.
  • Vulnerability Prioritization
    Prioritize vulnerabilities that matter based on the threat landscape and defer vulnerabilities that don't.
  • Early Warning System
    Real-time alerting of changes in the vulnerability landscape so that you can take action before the attacks start.
Schedule a Demo