CVE-2024-20355

CVE-2024-20355 is a medium-severity vulnerability in Cisco Adaptive Security Appliance Software with a CVSS 3.x base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-862.

Key facts

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.

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.
How severe is CVE-2024-20355?
CVE-2024-20355 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2024-20355 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-20355?
CVE-2024-20355 primarily affects Cisco Adaptive Security Appliance Software. In total, 227 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-20355?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-20355 have an EU (EUVD) identifier?
Yes. CVE-2024-20355 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-18070.
When was CVE-2024-20355 published?
CVE-2024-20355 was published on 2024-05-22 and last updated on 2026-06-17.

References

Affected products (227)

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