CVE intelligence and bounded remediation

CVE-2023-20247 — Cisco Adaptive Security Appliance Software security vulnerability

Medium CVSS 5

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.

Severity
Medium
CVSS
5 (3.1)
Published
2023-11-01
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-288

Affected products

  • cisco / adaptive_security_appliance_software / 9.8.1
  • cisco / adaptive_security_appliance_software / 9.8.1.5
  • cisco / adaptive_security_appliance_software / 9.8.1.7
  • cisco / adaptive_security_appliance_software / 9.8.2
  • cisco / adaptive_security_appliance_software / 9.8.2.8
  • cisco / adaptive_security_appliance_software / 9.8.2.14

Showing 6 representative product identities from 229 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authentication bypass and missing authentication

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Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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