{"id":"CVE-2025-54581","aliases":["GHSA-7h24-c332-p48c"],"url":"https://o3.security/vulnerability/CVE-2025-54581","summary":"vproxy is vulnerable to a divide by zero DoS attack","details":"### Summary\nUntrusted, user-controlled data from the HTTP Proxy-Authorization header can induce a denial of service state.\n\n### Details\nUntrusted data is extracted from the user-controlled HTTP Proxy-Authorization header and passed to Extension::try_from and flows into parse_ttl_extension where it is parsed as a TTL value. If an attacker supplies a TTL of zero (e.g. by using a username such as 'configuredUser-ttl-0'), the modulo operation 'timestamp % ttl' will cause a division by zero panic, causing the server to crash causing a denial-of-service.\n\nThe code assumed to be responsible for this can be found here: https://github.com/0x676e67/vproxy/blob/ab304c3854bf8480be577039ada0228907ba0923/src/extension.rs#L173-L183\n\n### PoC\n1. Download and run the latest version of vproxy\n2. Send a cUrl request like the following, adjusting address and port as necessary: ```curl -x \"http://test-ttl-0:test@127.0.0.1:8101\" https://google.com```\n3. Wait for a cUrl error indicating \"Proxy CONNECT aborted\"\n4. View logs from the vproxy server\n5. Observe that the vproxy server crashed due to a divide-by-zero panic\n\n### Impact\nThe resulting crash renders the proxy server unusable until it is reset.\n\nFinally, one last note: I'm reporting this on behalf of another researcher at Black Duck. Credit for discovery should be attributed to David Bohannon ([dbohannon](https://github.com/dbohannon))","published":"2025-07-30T19:57:46.454Z","modified":"2026-08-12T03:51:25.043023746Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.00541,"percentile":0.43059,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"vproxy","fixedVersion":"2.4.0"}],"fix":{"url":"https://github.com/0x676e67/vproxy/commit/aa1bf64c5e7f1c471395f9f29175ffc1b16a1079","label":"0x676e67/vproxy@aa1bf64"},"references":[{"type":"WEB","url":"https://github.com/0x676e67/vproxy/releases/tag/v2.4.0"},{"type":"ADVISORY","url":"https://github.com/0x676e67/vproxy/security/advisories/GHSA-7h24-c332-p48c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/54xxx/CVE-2025-54581.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-54581"},{"type":"FIX","url":"https://github.com/0x676e67/vproxy/commit/aa1bf64c5e7f1c471395f9f29175ffc1b16a1079"},{"type":"PACKAGE","url":"https://github.com/0x676e67/vproxy"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:25.043023746Z"}}