CVE-2025-23217 Mitmweb API Authentication Bypass Using Proxy Server
Attackers can bypass authentication via the proxy server to access internal APIs, potentially leading to remote code execution in mitmweb.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-23217?
CVE-2025-23217 is a high-severity authentication bypass vulnerability in mitmproxy, published on 6 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
mitmproxy is a interactive TLS-capable intercepting HTTP proxy for penetration testers and software developers and mitmweb is a web-based interface for mitmproxy. In mitmweb 11.1.1 and below, a malicious client can use mitmweb's proxy server (bound to `*:8080` by default) to access mitmweb's internal API (bound to `127.0.0.1:8081` by default). In other words, while the cannot access the API directly, they can access the API through the proxy. An attacker may be able to escalate this SSRF-style access to remote code execution. The mitmproxy and mitmdump tools are unaffected. Only mitmweb is affected. This vulnerability has been fixed in mitmproxy 11.1.2 and above. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Which versions are affected by CVE-2025-23217?
3 open source packages ship an affected version, including mitmproxy.
| Package | Affected | Fixed in |
|---|---|---|
mitmproxy PyPI | All versions | 11.1.2 |
mitmproxy PyPI | All versions | 11.1.2 |
mitmproxy PyPI | All versions | 11.1.2 |
How do I fix CVE-2025-23217?
Upgrade mitmproxy to 11.1.2 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2025-23217 being exploited?
There is no known exploitation of CVE-2025-23217 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2025-23217, GHSA-wg33-5h85-7q5p, PYSEC-2026-1630, UBUNTU-CVE-2025-23217.