{"id":"CVE-2009-4409","aliases":["EUVD-2009-4376","GHSA-8c96-xx6x-rr2w"],"status":"published","title":"The (1) CHAP and (2) MS-CHAP-V2 authentication capabilities in the PPP Access Concentrator (PPPAC...","description":"The (1) CHAP and (2) MS-CHAP-V2 authentication capabilities in the PPP Access Concentrator (PPPAC) function in Internet Initiative Japan SEIL/B1 firmware 1.00 through 2.52 use the same challenge for each authentication attempt, which allows remote attackers to bypass authentication via a replay attack.","severity":{"version":"2.0","score":2.6,"vector":"AV:N/AC:H/Au:N/C:N/I:P/A:N","level":"low","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.01356,"percentile":0.71825,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-287"],"published":"2009-12-23T21:00:00Z","modified":"2026-06-16T23:13:36Z","products":[{"vendor":"iij","product":"seil\\/b1"}],"references":[{"url":"http://secunia.com/advisories/37628","tags":["third-party-advisory","x_refsource_SECUNIA","x_transferred","Vendor Advisory"]},{"url":"http://www.securityfocus.com/bid/37293","tags":["vdb-entry","x_refsource_BID","x_transferred"]},{"url":"http://jvn.jp/en/jp/JVN49602378/index.html","tags":["third-party-advisory","x_refsource_JVN","x_transferred"]},{"url":"http://www.osvdb.org/61118","tags":["vdb-entry","x_refsource_OSVDB","x_transferred"]},{"url":"http://www.seil.jp/seilseries/security/2009/a00697.php","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory"]},{"url":"http://jvndb.jvn.jp/ja/contents/2009/JVNDB-2009-000079.html","tags":["third-party-advisory","x_refsource_JVNDB","x_transferred"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2009-4409"},{"url":"https://github.com/advisories/GHSA-8c96-xx6x-rr2w"}],"sources":{"cve":[{"id":"CVE-2009-4409","description":"The (1) CHAP and (2) MS-CHAP-V2 authentication capabilities in the PPP Access Concentrator (PPPAC) function in Internet Initiative Japan SEIL/B1 firmware 1.00 through 2.52 use the same challenge for each authentication attempt, which allows remote attackers to bypass authentication via a replay attack.","status":"published","published":"2009-12-23T21:00:00Z","modified":"2024-09-17T01:35:32.632Z","updated_at":"2026-11-02T14:33:24.782697Z"}],"euvd":[{"id":"EUVD-2009-4376","description":"The (1) CHAP and (2) MS-CHAP-V2 authentication capabilities in the PPP Access Concentrator (PPPAC) function in Internet Initiative Japan SEIL/B1 firmware 1.00 through 2.52 use the same challenge for each authentication attempt, which allows remote attackers to bypass authentication via a replay attack.","status":"published","published":"2009-12-23T21:00:00Z","modified":"2024-09-17T01:35:32Z","updated_at":"2026-11-03T00:28:48.402396Z"}],"ghsa":[{"id":"GHSA-8c96-xx6x-rr2w","title":"The (1) CHAP and (2) MS-CHAP-V2 authentication capabilities in the PPP Access Concentrator (PPPAC...","description":"The (1) CHAP and (2) MS-CHAP-V2 authentication capabilities in the PPP Access Concentrator (PPPAC) function in Internet Initiative Japan SEIL/B1 firmware 1.00 through 2.52 use the same challenge for each authentication attempt, which allows remote attackers to bypass authentication via a replay attack.","status":"published","published":"2022-05-02T03:54:25Z","modified":"2023-01-31T05:08:13Z","cwes":["CWE-287"],"updated_at":"2026-11-02T14:49:21.399059Z"}],"nvd":[{"id":"CVE-2009-4409","description":"The (1) CHAP and (2) MS-CHAP-V2 authentication capabilities in the PPP Access Concentrator (PPPAC) function in Internet Initiative Japan SEIL/B1 firmware 1.00 through 2.52 use the same challenge for each authentication attempt, which allows remote attackers to bypass authentication via a replay attack.","status":"published","published":"2009-12-23T21:30:00.313Z","modified":"2026-06-16T23:13:36.723Z","cvss":[{"version":"2.0","score":2.6,"vector":"AV:N/AC:H/Au:N/C:N/I:P/A:N","level":"low","assessor":"primary"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:01:38.33745Z"}]}}