CVEvulnerability

CVE-2021-1616

4.7 MEDIUM Published 2021-09-23 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2021-09-23
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
4.7 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
CVSS 3.1 ([email protected])
4.7 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
CVSS 2.0 ([email protected])
4.3 MEDIUM — AV:N/AC:M/Au:N/C:N/I:P/A:N
Weaknesses
CWE-693

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.

Affected configurations

• cisco ios xe (< 17.6.1)

Related

Weakness · CWE (1)

  • CWE-693 Protection Mechanism Failure weakness

References