CVE-2021-1616CWE-693

Cisco IOS XE Software H.323 Application Level Gateway Bypass Vulnerability

Medium · published September 23, 2021

CVSS v3.1
4.7
EPSS
1%
Percentile
67.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
4.7 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.01194 · 67.8th percentile
Weakness
CWE-693 · Protection Mechanism Failure
Published
2021-09-23T02:30Z
EPSS history
Timeline
  • 23 SEP 02:30Z
    Cisco IOS XE Software H.323 Application Level Gateway Bypass Vulnerability
    cvelistv5