CVE-2024-20337: A vulnerability in the SAML authentication process of Cisco Secure Client could allow an unauthenticated, remo

This week

HIGH 8.2UPGRADE

CVE-2024-20337 is a high-severity flaw (CVSS 8.2) affecting secure client. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 attacke

Why this priority

High severity
EPSS top 2%: very likely to be exploited

A fixed release or distro patch exists.

Risk facts

CVSS score	8.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	29.9% (top 2%)
CISA exploited list	No
Weakness	CWE-93
Published	2024-03-06
Last modified	2026-06-17

Publisher (CNA): Cisco Systems, Inc. · Vendor: cisco

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-03-06 17:15 UTCPublished CVE record published
2026-06-17 07:06 UTCUpdated Record last modified

cisco secure client UPGRADE

Affected: >= 4.10.04065 and < 4.10.08025 · >= 5.0.00529 and < 5.1.2.42

Fixed in: 4.10.08025, 5.1.2.42

Safe to downgrade to: a release before 4.10.04065

1. Check installed version

apt-cache policy secure-client || rpm -q secure-client || secure-client --version

2. UPGRADE to 4.10.08025 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade secure-client

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade secure-client

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 4.10.04065 (Debian / Ubuntu)

apt-cache madison secure-client sudo apt install secure-client=<VERSION_BEFORE_4.10.04065> sudo apt-mark hold secure-client

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list secure-client sudo dnf downgrade secure-client-<VERSION_BEFORE_4.10.04065> sudo dnf versionlock add secure-client

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2024-20337?

secure client: upgrade to 4.10.08025, 5.1.2.42. Exact commands for each OS are on this page.

Is CVE-2024-20337 being exploited?

CVE-2024-20337 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2024-20337 affect?

CVE-2024-20337 affects secure client. Severity is high (CVSS 8.2). 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 insuff

How urgent is CVE-2024-20337?

Priority 53/100. High severity; EPSS top 2%: very likely to be exploited

Software pages

Cisco vulnerabilities

Related CVEs

CVE-2023-20178 HIGH 7.8 UPGRADE UPGRADE A vulnerability in the client update process of Cisco AnyConnect Secure Mobility Client Software for Windows a
CVE-2025-20206 HIGH 7.1 UPGRADE A vulnerability in the interprocess communication (IPC) channel of Cisco Secure Client for Windows could allow
CVE-2024-3661 HIGH 7.6 UPGRADE UPGRADE DHCP can add routes to a client’s routing table via the classless static route option (121)
CVE-2024-20474 MEDIUM 4.3 DOWNGRADE DOWNGRADE A vulnerability in Internet Key Exchange version 2 (IKEv2) processing of Cisco Secure Client Software could al
CVE-2024-20338 HIGH 7.3 UPGRADE A vulnerability in the ISE Posture (System Scan) module of Cisco Secure Client for Linux could allow an authen

References

← Back to latest CVEs