Cisco EIGRP Protocol Unauthenticated Goodbye Packet Remote Denial Of Service Vulnerability

Bugtraq ID:	15978
Class:	Design Error
CVE:
Remote:	Yes
Local:	No
Published:	Dec 19 2005 12:00AM
Updated:	Dec 19 2005 12:00AM
Credit:	"Andrew A. Vladimirov" <[email protected]>, Arhont Ltd disclosed this issue.
Vulnerable:	Cisco EIGRP 1.2 + Cisco IOS 12.4 + Cisco IOS 12.3 + Cisco IOS 12.2 + Cisco IOS 12.1 + Cisco IOS 12.0 + Cisco IOS 0
Not Vulnerable:

Cisco EIGRP Protocol Unauthenticated Goodbye Packet Remote Denial Of Service Vulnerability

The Cisco EIGRP protocol is susceptible to a remote denial of service vulnerability. This issue is possible when MD5 neighbor authentication is not in use.

This issue allows attackers to cause routing relationships to be torn down, forcing them to be reestablished. The routing link will be unavailable during the time that the link is torn down, until it is reestablished. By repeating the attack, a sustained denial of network service is possible.

This issue is being tracked by Cisco Bug ID CSCsc13698.

Cisco EIGRP Protocol Unauthenticated Goodbye Packet Remote Denial Of Service Vulnerability

An exploit is not required.

Cisco EIGRP Protocol Unauthenticated Goodbye Packet Remote Denial Of Service Vulnerability

Solution:
Cisco has replied to the original email message and has confirmed this issue. Please see the referenced message for further information on mitigating this issue.

Cisco EIGRP Protocol Unauthenticated Goodbye Packet Remote Denial Of Service Vulnerability

References:

• Cisco Call Manager Express (Cisco Systems)
  
• Cisco IOS Software (Cisco Systems)
  
• Re: Unauthenticated EIGRP DoS ("Paul Oxman \(poxman\)" )