Cisco IOS fails to properly handle specially crafted VTP summary advertisement with overly long VLAN name. This vulnerability may allow a remote, unauthenticated attacker to execute arbitrary code or cause a denial-of-service condition.
Cisco's VLAN Trunking Protocol (VTP) provides the ability to manage the addition, deletion, and renaming of Virtual Local Area Networks (VLANs) across an entire network. VTP is supported on a number of different Cisco products in both the IOS and CatOS operating systems. Some versions of IOS and CatOS contain a buffer overflow vulnerability in their handling of certain VTP summary advertisements. According to Cisco Systems:
If a VTP summary advertisement is received with a Type-Length-Value (TLV) containing a VLAN name greater than 100 characters, the receiving switch will reset with an Unassigned Exception error. The packets must be received on a trunk enabled port, with a matching domain name and a matching VTP domain password (if configured).
This vulnerability may allow a remote, unauthenticated attacker to execute arbitrary code or cause a denial-of-service condition on an affected device.
We are unaware of a complete solution to this problem. In the meantime, the following workarounds may help to mitigate this vulnerability.
Apply a VTP domain password
This issue was reported in Cisco Security Response cisco-sr-20060913-vtp. Cisco credits FX of Phenoelit for reporting this issue.
This document was written by Chris Taschner.
|Date First Published:||2006-09-27|
|Date Last Updated:||2006-09-27 20:39 UTC|