← Vulnerability feed

Vulnerability record · CVE-2024-20337 · published 6 March 2024

CVE-2024-20337: Cisco secure client vulnerability

Cisco · Secure Client

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.

8.2 CVSS 3.1 High EPSS 30% · top 1.9% CWE-93 · CWE-93
8.2CVSS 3.1 base score
30%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-secure-client-crlf-W43V4G7 Vendor Advisory
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-secure-client-crlf-W43V4G7 Vendor Advisory

Track CVE-2024-20337 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.8CVE-2025-20206Cisco secure client improper verification of cryptographic signature vulnerabilityA vulnerability in the interprocess communication (IPC) channel of Cisco Secure Client for Windows could allow an authenticated, local attacker to pe…EPSS 0.18%7.8CVE-2023-20178Cisco anyconnect secure mobility client incorrect default permissions vulnerabilityA vulnerability in the client update process of Cisco AnyConnect Secure Mobility Client Software for Windows and Cisco Secure Client Software for Win…EPSS 5.4%7.6CVE-2024-3661Fortinet forticlient missing authentication for critical function vulnerabilityDHCP can add routes to a client’s routing table via the classless static route option (121). VPN-based security solutions that rely on routes to redi…EPSS 4.1%7.3CVE-2024-20338Cisco secure client uncontrolled search path element vulnerabilityA vulnerability in the ISE Posture (System Scan) module of Cisco Secure Client for Linux could allow an authenticated, local attacker to elevate priv…EPSS 0.89%6.8CVE-2024-20391Cisco secure client missing authentication for critical function vulnerabilityA vulnerability in the Network Access Manager (NAM) module of Cisco Secure Client could allow an unauthenticated attacker with physical access to an …EPSS 0.35%6.5CVE-2024-20474Cisco anyconnect secure mobility client vulnerabilityA vulnerability in Internet Key Exchange version 2 (IKEv2) processing of Cisco Secure Client Software could allow an unauthenticated, remote attacker…EPSS 0.60%5.5CVE-2023-20240Cisco anyconnect secure mobility client out-of-bounds read vulnerabilityMultiple vulnerabilities in Cisco Secure Client Software, formerly AnyConnect Secure Mobility Client, could allow an authenticated, local attacker to…EPSS 0.20%5.5CVE-2023-20241Cisco anyconnect secure mobility client out-of-bounds read vulnerabilityMultiple vulnerabilities in Cisco Secure Client Software, formerly AnyConnect Secure Mobility Client, could allow an authenticated, local attacker to…EPSS 0.20%

Source: NIST National Vulnerability Database (record CVE-2024-20337), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.