Cisco VPN 3000 series concentrators HTML parser denial of service

cisco-vpn-html-parser-dos (10018) The risk level is classified as MediumMedium Risk


Cisco VPN 3000 series concentrators are vulnerable to a denial of service attack, caused by a vulnerability in the HTML parser. A remote attacker could send an overly long HTTP request to the server to consume 100% of the available CPU resources, which would cause the server to stop responding. The device would regain normal functionality after about 5 minutes.


Denial of Service


Upgrade to the latest software version for your device (3.6(Rel) or later), (3.5(Rel) or later), (3.1(Rel) or later), or (3.0.3(B) or later), as listed in Cisco Security Advisory: Cisco VPN 3000 Concentrator Multiple Vulnerabilities. See References.


  • CIAC Information Bulletin M-119: Cisco VPN Concentrators and VPN 3002 Client Multiple Vulnerabilities.
  • vpn3k-multiple-vuln-pub: Cisco Security Advisory: Cisco VPN 3000 Concentrator Multiple Vulnerabilities.
  • BID-5609: Multiple Cisco VPN 3000 Vulnerabilities
  • BID-5615: Cisco HTTP Interface Long Request Denial Of Service Vulnerability
  • CVE-2002-1093: HTML interface for Cisco VPN 3000 Concentrator 2.x.x and 3.x.x before 3.0.3(B) allows remote attackers to cause a denial of service (CPU consumption) via a long URL request.
  • OSVDB ID: 8908: Cisco VPN 3000 Concentrator HTML Interface Long URL DoS

Platforms Affected:

  • Cisco VPN 3000 Concentrator 2.0
  • Cisco VPN 3000 Concentrator 2.5.2.A
  • Cisco VPN 3000 Concentrator 2.5.2.B
  • Cisco VPN 3000 Concentrator 2.5.2.C
  • Cisco VPN 3000 Concentrator 2.5.2.D
  • Cisco VPN 3000 Concentrator 2.5.2.F
  • Cisco VPN 3000 Concentrator 3.0
  • Cisco VPN 3000 Concentrator 3.0(Rel)
  • Cisco VPN 3000 Concentrator 3.0.3.A


Sep 03, 2002

The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (IBM Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

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