CVE-2021-1616

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

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.

Category

4.7
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.81% Top 30%
Vendor Advisory cisco.com
Affected: Cisco Cisco IOS XE Software
Published at:
Updated at:

References

Link Tags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-h323alg-bypass-4vy2MP2Q vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-1616?
CVE-2021-1616 has been scored as a medium severity vulnerability.
How to fix CVE-2021-1616?
To fix CVE-2021-1616, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-1616 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-1616 is being actively exploited. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-1616?
CVE-2021-1616 affects Cisco Cisco IOS XE Software.
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