CVE-2009-4409: The (1) CHAP and (2) MS-CHAP-V2 authentication capabilities in the PPP Access Concentrator (PPPAC) function...

Security readout for executives and security teams

A SEIL/B1 network access function reused the same authentication challenge, weakening CHAP and MS-CHAP-V2 logins. A remote attacker could reuse captured authentication material to bypass access controls. Business risk is highest where affected devices still provide PPP access to internal networks. Exposure is likely limited to organizations still operating SEIL/B1 devices with firmware 1.00 through 2.52 and PPPAC CHAP or MS-CHAP-V2 enabled, especially if reachable from untrusted networks. Treat as high priority if affected SEIL/B1 devices still gate remote or partner access. The vulnerability can bypass authentication, but current exploitation evidence is not provided. Mitigation focus: Inventory SEIL/B1 devices and firmware versions.; Check SEIL and JVN guidance for fixed firmware or vendor mitigation.; Disable PPPAC CHAP and MS-CHAP-V2 where operationally feasible..

Prepared

Jun 28, 2026, 09:59 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.