{"id":"CVE-2025-23217","aliases":["GHSA-wg33-5h85-7q5p","PYSEC-2026-1630"],"url":"https://o3.security/vulnerability/CVE-2025-23217","summary":"Mitmweb API Authentication Bypass Using Proxy Server","details":"### Impact\nIn mitmweb 11.1.0 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 client cannot access the API directly (good), they can access the API through the proxy (bad). An attacker may be able to escalate this [SSRF](https://en.wikipedia.org/wiki/Server-side_request_forgery)-style access to remote code execution.\n\nThe mitmproxy and mitmdump tools are unaffected. Only mitmweb is affected. The `block_global` option, which is enabled by default, blocks connections originating from publicly-routable IP addresses in the proxy. The attacker needs to be in the same local network.\n\n### Patches\n\nThe vulnerability has been fixed in mitmproxy 11.1.2 and above.\n\n### Acknowledgements\n\nWe thank Stefan Grönke (@gronke) for reporting this vulnerability as part of a security audit by [Radically Open Security](https://www.radicallyopensecurity.com/). This audit was supported by the [NGI0 Entrust fund](https://nlnet.nl/entrust/) established by [NLnet](https://nlnet.nl/).\n\n### Timeline\n\n- **2025-01-14**: Received initial report. \n- **2025-01-14**: Verified report and confirmed receipt.\n- **2025-01-19**: Shared patch with researcher.\n- **2025-02-04**: Received final confirmation that patch is working.\n- **2025-02-05**: Published patched release and advisory.","published":"2025-02-06T17:32:30.226Z","modified":"2026-10-28T02:30:54.627701541Z","cvss":null,"epss":{"score":0.00831,"percentile":0.55859,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"mitmproxy","fixedVersion":"11.1.2"}],"fix":{"url":"https://github.com/mitmproxy/mitmproxy/commit/fa89055e196d953f11fd241e36ee37858993486a","label":"mitmproxy/mitmproxy@fa89055"},"references":[{"type":"WEB","url":"https://en.wikipedia.org/wiki/Server-side_request_forgery"},{"type":"WEB","url":"https://github.com/mitmproxy/mitmproxy/blob/main/CHANGELOG.md#06-february-2025-mitmproxy-1112"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/23xxx/CVE-2025-23217.json"},{"type":"ADVISORY","url":"https://github.com/mitmproxy/mitmproxy/security/advisories/GHSA-wg33-5h85-7q5p"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-23217"},{"type":"WEB","url":"https://github.com/mitmproxy/mitmproxy/commit/fa89055e196d953f11fd241e36ee37858993486a"},{"type":"PACKAGE","url":"https://github.com/mitmproxy/mitmproxy"},{"type":"WEB","url":"https://github.com/mitmproxy/mitmproxy/blob/main/CHANGELOG.md"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:30:54.627701541Z"}}