Cisco » IOS : Security Vulnerabilities, CVEs, Published In September 2006 (Overflow)

Heap-based buffer overflow in the VLAN Trunking Protocol (VTP) feature in Cisco IOS 12.1(19) allows remote attackers to execute arbitrary code via a long VLAN name in a VTP type 2 summary advertisement.

Cisco IOS 12.0, 12.1, and 12.2, when GRE IP tunneling is used and the RFC2784 compliance fixes are missing, does not verify the offset field of a GRE packet during decapsulation, which leads to an integer overflow that references data from incorrect memory locations, which allows remote attackers to inject crafted packets into the routing queue, possibly bypassing intended router ACLs.