ProxyAgent vulnerable to MITM

Description

Undici.ProxyAgent never verifies the remote server’s certificate, and always exposes all request & response data to the proxy. This unexpectedly means that proxies can MitM all HTTPS traffic, and if the proxy’s URL is HTTP then it also means that nominally HTTPS requests are actually sent via plain-text HTTP between Undici and the proxy server.

Recommendation

Update the undici package to the latest compatible version. Followings are version details:

• Affected version(s): >= 4.8.2, <= 5.5.0
• Patched version(s): 5.5.1

References

• GHSA-pgw7-wx7w-2w33
• hackerone.com
• CVE-2022-32210
• CWE-295
• CAPEC-310
• OWASP 2021-A6
• OWASP 2021-A7

Related Issues

• jsPDF Denial of Service (DoS) - CVE-2025-57810
• undici Denial of Service attack via bad certificate data - CVE-2025-47279
• MailDev Remote Code Execution - CVE-2024-27448
• Undici's Proxy-Authorization header not cleared on cross-origin redirect for dispatch, request, stream, pipeline - CVE-2024-30260

Tags:

npm

undici