{"cve":"CVE-2009-3727","nvd":{"published":"2009-11-10T18:30:00.250","modified":"2026-06-16T23:12:14.750","status":"Modified","description":"Asterisk Open Source 1.2.x before 1.2.35, 1.4.x before 1.4.26.3, 1.6.0.x before 1.6.0.17, and 1.6.1.x before 1.6.1.9; Business Edition A.x.x, B.x.x before B.2.5.12, C.2.x.x before C.2.4.5, and C.3.x.x before C.3.2.2; AsteriskNOW 1.5; and s800i 1.3.x before 1.3.0.5 generate different error messages depending on whether a SIP username is valid, which allows remote attackers to enumerate valid usernames via multiple crafted REGISTER messages with inconsistent usernames in the URI in the To header and the Digest in the Authorization header.","cvss_v4":null,"cvss_v3":null,"cwes":["CWE-200"],"references":["http://downloads.asterisk.org/pub/security/AST-2009-008.html","http://osvdb.org/59697","http://secunia.com/advisories/37265","http://secunia.com/advisories/37479","http://secunia.com/advisories/37677"],"products":["digium:asterisk","digium:asterisknow","digium:s800i"],"source":"nvd","synced_at":"2026-10-19T19:54:26.868835795+00:00"},"epss":{"cve":"CVE-2009-3727","score":0.04201,"percentile":0.9096,"date":"2026-10-31"},"kev":null,"osv":[],"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."]}