CVE intelligence and bounded remediation

CVE-2024-20355 — Cisco Adaptive Security Appliance Software security vulnerability

Medium CVSS 5

A vulnerability in the implementation of SAML 2.0 single sign-on (SSO) for remote access VPN services in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to successfully establish a VPN session on an affected device. This vulnerability is due to improper separation of authorization domains when using SAML authentication. An attacker could exploit this vulnerability by using valid credentials to successfully authenticate using their designated connection profile (tunnel group), intercepting the SAML SSO token that is sent back from the Cisco ASA device, and then submitting the same SAML SSO token to a different tunnel group for authentication. A successful exploit could allow the attacker to establish a remote access VPN session using a connection profile that they are not authorized to use and connect to secured networks behind the affected device that they are not authorized to access. For successful exploitation, the attacker must have valid remote access VPN user credentials.

Severity
Medium
CVSS
5 (3.1)
Published
2024-05-22
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-862

Affected products

  • cisco / adaptive_security_appliance_software / 9.8.2.28
  • cisco / adaptive_security_appliance_software / 9.8.2.33
  • cisco / adaptive_security_appliance_software / 9.8.2.35
  • cisco / adaptive_security_appliance_software / 9.8.2.38
  • cisco / adaptive_security_appliance_software / 9.8.3
  • cisco / adaptive_security_appliance_software / 9.8.3.8

Showing 6 representative product identities from 227 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

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