VULNERABILITY INTELLIGENCE

CVE-2021-34790

CVSS score4.7 MEDIUM
EPSS probability1.15%
CISA KEVNot currently listed
Published2021-10-27
Last modified2026-08-11
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Description

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.

Weakness classification

  • psirt@cisco.com: CWE-358
  • nvd@nist.gov: CWE-20

Primary references