Cisco Security Advisory – Cisco IOS contains multiple vulnerabilities in the Data-link Switching (DLSw) feature that may result in a reload or memory leaks when processing specially crafted UDP or IP Protocol 91 packets. Cisco has released free software updates that address these vulnerabilities. Workarounds are available to mitigate the effects of these vulnerabilities.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/64920/cisco-sa-20080326-dlsw.txt
Source: https://packetstormsecurity.com/files/64920/Cisco-Security-Advisory-20080326-dlsw.html