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Fencer Vulns
medium 5.0

CVE-2023-20247 json

A vulnerability in the remote access SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense…

published 2023-11-01 3 y ago modified 2026-08-11 2 mo ago also EUVD-2023-24426

cvss
5.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

A vulnerability in the remote access SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to bypass a configured multiple certificate authentication policy and connect using only a valid username and password. This vulnerability is due to improper error handling during remote access VPN authentication. An attacker could exploit this vulnerability by sending crafted requests during remote access VPN session establishment. A successful exploit could allow the attacker to bypass the configured multiple certificate authentication policy while retaining the privileges and permissions associated with the original connection profile.

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
16 mo ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.0 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
NVD 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Affected products

  • Cisco Cisco Adaptive Security Appliance (ASA) Software
  • Cisco Cisco Firepower Threat Defense Software

Classification

Weakness
  • CWE-288 Authentication Bypass Using an Alternate Path or Channel

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.