Vulnerability Monitor

The vendors, products, and vulnerabilities you care about

CVE-2021-1616

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.

Published

2021-09-23T03:15:12.627

Last Modified

2024-11-21T05:44:44.827

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 4.7 (MEDIUM)

CVSSv2 Vector

AV:N/AC:M/Au:N/C:N/I:P/A:N

Access Vector: NETWORK
Access Complexity: MEDIUM
Authentication: NONE
Confidentiality Impact: NONE
Integrity Impact: PARTIAL
Availability Impact: NONE

Exploitability Score

8.6

Impact Score

2.9

Weaknesses

Type: Secondary
CWE-693
Type: Primary
NVD-CWE-Other

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Operating System	cisco	ios_xe	< 17.6.1	Yes

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-h323alg-bypass-4vy2MP2Q Vendor Advisory ([email protected])
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-h323alg-bypass-4vy2MP2Q Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)