SB2021020507 - IPV6 ACL bypass in Cisco IOS XR and Cisco NX-OS Software
Published: February 5, 2021
Security Bulletin ID
SB2021020507
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Improper access control (CVE-ID: CVE-2021-1389)
The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.
The vulnerability exists due to improper access restrictions when processing IPv6 traffic in Cisco IOS XR Software and Cisco NX-OS Software for certain Cisco devices. A remote attacker can bypass implemented ACLs with specially crafted IPv6 packets.
this vulnerability affected the following Cisco devices if they were running a vulnerable release of Cisco IOS XR Software or Cisco NX-OS Software and had IPv6 ACL configured:
- Network Convergence System (NCS) 540 Series Routers
- NCS 560 Series Routers
- NCS 5500 Series
- Nexus 3600 Platform Switches
- Nexus 9500 R-Series Switching Platforms
Remediation
Install update from vendor's website.