Cisco ASA clientless SSL VPN denial of service vulnerability

ID VU:337508
Type cert
Reporter CERT
Modified 2007-05-04T00:00:00



The Cisco ASA firewall's SSL VPN component contains an denial-of-service vulnerability.


The Cisco Adaptive Security Appliance (ASA) is firewall that includes routing, intrusion prevention system (IPS), and VPN components. The clientless SSL VPN allows remote users with a web browser to connect to internal web sites by tunneling an HTTPS session through the ASA.

The ASA's SSL VPN component contains a denial of service vulnerability.

Per Cisco Security Advisory cisco-sa-20070502-asa:
A successful attack must exploit a race condition in the processing non-standard SSL sessions and may result in a reload of the device.


A remote unauthenticated attacker may be able to to create a denial-of-service condition. Note that any systems that rely on the affected device would also be affected.



Cisco has released an update to address this vulnerability. See the Software Versions and Fixes section of Cisco Security Advisory cisco-sa-20070502-asa for more details.

Systems Affected

Vendor| Status| Date Notified| Date Updated
Cisco Systems, Inc.| | -| 03 May 2007
Cisco Systems, Inc.| | -| 03 May 2007
If you are a vendor and your product is affected, let us know.

CVSS Metrics

Group | Score | Vector
Base | N/A | N/A
Temporal | N/A | N/A
Environmental | N/A | N/A


  • <>
  • <>
  • <>
  • <>
  • <>
  • <>
  • <>


Thanks to Cisco for information that was used in this report.

This document was written by Ryan Giobbi.

Other Information

  • CVE IDs: Unknown
  • Date Public: 02 May 2007
  • Date First Published: 03 May 2007
  • Date Last Updated: 04 May 2007
  • Severity Metric: 0.70
  • Document Revision: 11