# CVE-2024-20337

## Summary

- **CVE ID:** CVE-2024-20337
- **Severity:** HIGH
- **CVSS Score:** 8.2 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N)
- **CWE:** CWE-93
- **Published:** Mar 6, 2024
- **Last Modified:** Mar 13, 2026

## 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 — Cisco Secure Client (4.9.00086)
- Cisco — Cisco Secure Client (4.9.01095)
- Cisco — Cisco Secure Client (4.9.02028)
- Cisco — Cisco Secure Client (4.9.03047)
- Cisco — Cisco Secure Client (4.9.03049)
- Cisco — Cisco Secure Client (4.9.04043)
- Cisco — Cisco Secure Client (4.9.04053)
- Cisco — Cisco Secure Client (4.9.05042)
- Cisco — Cisco Secure Client (4.9.06037)
- Cisco — Cisco Secure Client (4.10.00093)
- Cisco — Cisco Secure Client (4.10.01075)
- Cisco — Cisco Secure Client (4.10.02086)
- Cisco — Cisco Secure Client (4.10.03104)
- Cisco — Cisco Secure Client (4.10.04065)
- Cisco — Cisco Secure Client (4.10.04071)
- Cisco — Cisco Secure Client (4.10.05085)
- Cisco — Cisco Secure Client (4.10.05095)
- Cisco — Cisco Secure Client (4.10.05111)
- Cisco — Cisco Secure Client (4.10.06079)
- Cisco — Cisco Secure Client (4.10.06090)
- Cisco — Cisco Secure Client (4.10.07061)
- Cisco — Cisco Secure Client (4.10.07062)
- Cisco — Cisco Secure Client (4.10.07073)
- Cisco — Cisco Secure Client (5.0.00238)
- Cisco — Cisco Secure Client (5.0.00529)
- Cisco — Cisco Secure Client (5.0.00556)
- Cisco — Cisco Secure Client (5.0.01242)
- Cisco — Cisco Secure Client (5.0.02075)
- Cisco — Cisco Secure Client (5.0.03072)
- Cisco — Cisco Secure Client (5.0.03076)
- Cisco — Cisco Secure Client (5.0.04032)
- Cisco — Cisco Secure Client (5.0.05040)
- Cisco — Cisco Secure Client (5.1.0.136)
- Cisco — Cisco Secure Client (5.1.1.42)

## References

- [CNA](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-secure-client-crlf-W43V4G7)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 31.02%
- **EPSS Percentile:** 98.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._