{"cve":"CVE-2024-21491","nvd":{"published":"2024-02-13T05:15:08.873","modified":"2026-06-17T07:09:36.273","status":"Modified","description":"Versions of the package svix before 1.17.0 are vulnerable to Authentication Bypass due to an issue in the verify function where signatures of different lengths are incorrectly compared. An attacker can bypass signature verification by providing a shorter signature that matches the beginning of the actual signature.\r\r**Note:**\r\rThe attacker would need to know a victim uses the Rust library for verification,no easy way to automatically check that; and uses webhooks by a service that uses Svix, and then figure out a way to craft a malicious payload that will actually include all of the correct identifiers needed to trick the receivers to cause actual issues.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","score":6.5},"cwes":["CWE-347","CWE-288"],"references":["https://github.com/svix/svix-webhooks/commit/958821bd3b956d1436af65f70a0964d4ffb7daf6","https://github.com/svix/svix-webhooks/pull/1190","https://rustsec.org/advisories/RUSTSEC-2024-0010.html","https://security.snyk.io/vuln/SNYK-RUST-SVIX-6230729","https://github.com/svix/svix-webhooks/commit/958821bd3b956d1436af65f70a0964d4ffb7daf6"],"products":["svix:svix-webhooks"],"source":"nvd","synced_at":"2026-10-19T21:45:59.823092188+00:00"},"epss":{"cve":"CVE-2024-21491","score":0.0041,"percentile":0.35256,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-747x-5m58-mq97","url":"https://osv.dev/vulnerability/GHSA-747x-5m58-mq97","summary":"svix vulnerable to Authentication Bypass","modified":"2024-10-16T17:06:15Z","packages":[{"ecosystem":"crates.io","name":"svix","purl":"pkg:cargo/svix","ranges":["<1.17.0"],"fixed":["1.17.0"]}]},{"id":"RUSTSEC-2024-0010","url":"https://osv.dev/vulnerability/RUSTSEC-2024-0010","summary":"Improper comparison of different-length signatures","modified":"2024-02-15T01:26:41.857241Z","packages":[{"ecosystem":"crates.io","name":"svix","purl":"pkg:cargo/svix","ranges":[">=0.0.0-0 <1.17.0"],"fixed":["1.17.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}