Preview Tool

Cisco Bug: CSCvu23797 - Cisco StarOS IPv6 Denial of Service Vulnerability

Last Modified

Sep 17, 2020

Products (2)

  • Cisco ASR 5000 Series
  • Cisco ASR 5500

Known Affected Releases

21.15.48 21.16.6 21.16.c14 21.18.3 21.20.0

Description (partial)

A vulnerability in the IPv6 implementation of Cisco StarOS could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

The vulnerability is due to insufficient validation of incoming IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet to an affected device with the goal of reaching the vulnerable section of the input buffer. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

This vulnerability is specific to IPv6 traffic. IPv4 traffic is not affected.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

This advisory is available at the following link:

At the time of publication, this vulnerability affected the following Cisco products if they were running a release of Cisco StarOS earlier than Release 21.18.3 and had the Vector Packet Processing (VPP) feature enabled:

Cisco ASR 5000 Series Aggregation Services Routers
Cisco Virtualized Packet Core-Single Instance (VPC-SI)

At the time of publication, Cisco StarOS releases 21.18.3 and later contained the fix for this vulnerability.
Bug details contain sensitive information and therefore require a account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.