CVE-2021-1616: cisco cisco ios xe software Protection Mechanism Failure

Vulnerability summary

CVE-2021-1616 is a medium (CVSS 4.7) Protection Mechanism Failure vulnerability in cisco cisco ios xe software. EPSS estimates a 1.19% chance of exploitation in the next 30 days, higher than 67.7% of scored vulnerabilities.

Timeline

1. 23-09-2021
   PublishedVulnerability first disclosed.
2. 07-11-2024
   Last modifiedVulnerability information updated.

Description

A vulnerability in the H.323 application level gateway (ALG) used by the Network Address Translation (NAT) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass the ALG. This vulnerability is due to insufficient data validation of traffic that is traversing the ALG. An attacker could exploit this vulnerability by sending crafted traffic to a targeted device. A successful exploit could allow the attacker to bypass the ALG and open connections that should not be allowed to a remote device located behind the ALG. Note: This vulnerability has been publicly discussed as NAT Slipstreaming.

• CWE-693Protection Mechanism FailureThe product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.