Cisco Security Advisory – Cisco IOS software contains two vulnerabilities within the Cisco IOS WebVPN or Cisco IOS SSLVPN feature (SSLVPN) that can be remotely exploited without authentication to cause a denial of service condition. A crafted HTTPS packet will crash device. SSLVPN sessions cause a memory leak in the device.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/76061/cisco-sa-20090325-webvpn.txt
Source: https://packetstormsecurity.com/files/76061/Cisco-Security-Advisory-20090325-webvpn.html