CVE-2024-20355

MEDIUM
Published May 22, 2024 Modified Jul 30, 2025 CWE-862

Description

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.

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CVSS v3.1 Score

5.0
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N

Weakness Type (CWE)

CWE-862 Missing Authorization

Affected Products

Vendor Product
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco adaptive_security_appliance_software
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense
cisco firepower_threat_defense

References

Frequently Asked Questions

What is CVE-2024-20355? +
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. It has a CVSS v3.1 base score of 5.0 (MEDIUM).
How severe is CVE-2024-20355? +
CVE-2024-20355 has a CVSS v3.1 score of 5.0 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2024-20355? +
CVE-2024-20355 affects products from cisco, specifically: adaptive_security_appliance_software, firepower_threat_defense. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2024-20355? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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