CVE-2021-34790
MEDIUMCisco Adaptive Security Appliance and Firepower Threat Defense - Unauthenticated NAT ALG Security Bypass
Title source: llmDescription
Multiple vulnerabilities in the Application Level Gateway (ALG) for the Network Address Translation (NAT) feature of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass the ALG and open unauthorized connections with a host located behind the ALG. For more information about these vulnerabilities, see the Details section of this advisory. Note: These vulnerabilities have been publicly discussed as NAT Slipstreaming.
References (1)
Core 1
Core References
Vendor Advisory vendor-advisory
x_refsource_cisco
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-natalg-bypass-cpKGqkng
Scores
CVSS v3
4.7
EPSS
0.0110
EPSS Percentile
61.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-358
CWE-20
Status
published
Products (19)
cisco/adaptive_security_appliance
< 9.8.4.40
cisco/adaptive_security_appliance_software
9.12.0 - 9.12.4.29
cisco/asa_5505_firmware
009.008
cisco/asa_5505_firmware
009.015
cisco/asa_5512-x_firmware
009.008
cisco/asa_5512-x_firmware
009.015
cisco/asa_5515-x_firmware
009.008
cisco/asa_5515-x_firmware
009.015
cisco/asa_5525-x_firmware
009.008
cisco/asa_5525-x_firmware
009.015
... and 9 more
Published
Oct 27, 2021
Tracked Since
Feb 18, 2026