CVE-2024-20337

Severity: high (CVSS 8.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 29.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-03-06 · updated 2026-06-17
Weakness: CWE-93

Description

A vulnerability in the SAML authentication process of Cisco Secure Client could allow an unauthenticated, remote attacker to conduct a carriage return line feed (CRLF) injection attack against a user. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a crafted link while establishing a VPN session. A successful exploit could allow the attacker to execute arbitrary script code in the browser or access sensitive, browser-based information, including a valid SAML token. The attacker could then use the token to establish a remote access VPN session with the privileges of the affected user. Individual hosts and services behind the VPN headend would still need additional credentials for successful access.

Affected products

Cisco Secure Client: from 4.10.04065 before 4.10.08025; from 5.0.00529 before 5.1.2.42 — fixed in 4.10.08025, 5.1.2.42

How to fix

Upgrade to a fixed version: Cisco Secure Client 4.10.08025, 5.1.2.42. Check the vendor advisory for mitigations.

References

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