CVE-2001-0427: Cisco VPN 3000 series concentrators before 2.5.2(F) allow remote attackers to cause a denial of service via...

Security readout for executives and security teams

This old Cisco VPN 3000 concentrator issue could let a remote attacker disrupt VPN service by flooding invalid login attempts. The business impact is availability: remote access users could lose VPN connectivity if an exposed affected concentrator is still in use. Exposure is likely limited to legacy Cisco VPN 3000 concentrators running versions before 2.5.2(F), especially where SSL or telnet access is reachable from untrusted networks. Treat as a legacy exposure cleanup item unless the affected VPN is still internet-facing or business-critical. Prioritize remediation if remote access availability depends on these devices. Mitigation focus: Identify any Cisco VPN 3000 concentrators still deployed.; Upgrade affected concentrators to 2.5.2(F) or later per Cisco guidance.; Review Cisco's advisory for any service-specific hardening guidance..

Prepared

Jul 1, 2026, 08:27 UTC (UTC+00:00)

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