How severe is CVE-2024-20439?

CVE-2024-20439 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which products are affected by CVE-2024-20439?

Affected package information for CVE-2024-20439 is not yet fully mapped. Check the official advisory links for details.

How do I patch CVE-2024-20439?

No patch has shipped for CVE-2024-20439 yet — track the cisco cisco smart license utility advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2024-20439 across my infrastructure?

Inventory every cisco cisco smart license utility deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

How do I mitigate CVE-2024-20439 if there is no patch (or I can't update yet)?

Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

How does O3 Security protect against CVE-2024-20439?

O3 detects and blocks CVE-2024-20439 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Is CVE-2024-20439 actively exploited in the wild?

No public exploit code has been indexed for CVE-2024-20439 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2024-20439?

CVE-2024-20439 has an EPSS (Exploit Prediction Scoring System) score of 92.1%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2024-20439 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2024-20439 (Cisco Smart Licensing Utility Static Credential Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2025-03-31. CISA required all US federal civilian agencies to remediate this vulnerability by 2025-04-21. The required action was: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2024-20439?

CVE-2024-20439 is classified as CWE-912 (CWE-912), Hard-coded Credentials (CWE-798). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2024-20439?

CVE-2024-20439 affects cisco cisco smart license utility. Check the affected-products list on this page against your deployed version to confirm exposure.

Is there exploit tooling available for CVE-2024-20439?

A Nuclei detection template exists for CVE-2024-20439, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2024-20439 published, and has it been updated?

CVE-2024-20439 was published on September 4, 2024 and was last updated on October 21, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2025-03-31 — agencies required to remediate by 2025-04-21

CVE-2024-20439

CRITICAL

A vulnerability in Cisco Smart Licensing Utility (CSLU) could allow an unauthenticated, remote attacker to log into an affected system by using a static administrative credential. …

Published

Sep 4, 2024

Updated

Oct 21, 2025

Affected

0 pkgs

Patched

None yet

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

92.1%probability of exploitation in next 30 days

Very High Risk100th percentile+0.05%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

A vulnerability in Cisco Smart Licensing Utility (CSLU) could allow an unauthenticated, remote attacker to log into an affected system by using a static administrative credential.

This vulnerability is due to an undocumented static user credential for an administrative account. An attacker could exploit this vulnerability by using the static credentials to login to the affected system. A successful exploit could allow the attacker to login to the affected system with administrative rights over the CSLU application API.

Affected Products

1 product · 3 configurations

Application

cisco smart license utilitycisco

all

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every cisco cisco smart license utility deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2024-20439 yet — track the cisco cisco smart license utility advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2024-20439 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2024-20439. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

A vulnerability in Cisco Smart Licensing Utility (CSLU) could allow an unauthenticated, remote attacker to log into an affected system by using a static administrative credential. This vulnerability is due to an undocumented static user credential for an administrative account. An attacker could exploit this vulnerability by using the static credentials to login to the affected system. A successful exploit could allow the attacker to login to the affected system with administrative rights over the CSLU application API.

O3 Security · Runtime Protection

Is CVE-2024-20439 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2024-20439 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

Protect my workloads How runtime protection works

CVE-2024-20439

EPSS Exploitation Probability

Description

Affected Products

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

How O3 protects you

Frequently Asked Questions

Is CVE-2024-20439 being exploited in your environment?