# CVE-2024-20439: Cisco Smart License Utility - Authentication Bypass

> Live exploitation tracking for CVE-2024-20439 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2024-20439

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 9.8
- **Public exploit available:** Yes
- **Affected products:** Cisco Smart License Utility
- **Weaknesses:** CWE-912 (Hidden Functionality)

## 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.

## CrowdSec analysis

[CVE-2024-20439](https://euvd.enisa.europa.eu/vulnerability/CVE-2024-20439) is a critical vulnerability in Cisco Smart Licensing Utility that allows attackers to gain administrative access through the use of a static credential.

CrowdSec has been tracking this vulnerability and its exploits since 3rd of April 2025.

Insights from the CrowdSec network reveal that the attackers trying to exploit CVE-2024-20439 are composed of a fairly even mix of opportunistic and targeted actors. Some attackers employ preliminary reconnaissance, while others use indiscriminate scanning.
Telemetry from the CrowdSec network also shows that exploitation activity for CVE-2024-20439 remains steady week-over-week. Attack volumes are consistent with long-term trends, indicating sustained interest from threat actors. CVE-2024-20439 continues to be an active part of the threat landscape and will likely remain this way for the forseeable future.

Observed exploitation attempts typically focus on URLs containing `/cslu/v1/scheduler/jobs`.

## Timeline

- 2024-09-04: CVE Published. CVE-2024-20439 is published to NVD.
- 2025-03-31: CISA KEV. CVE-2024-20439 is added to the Known Exploited Vulnerabilities catalog by CISA.
- 2025-04-03: Rule Released. CrowdSec releases a rule to detect CVE-2024-20439 exploitation attempts against the CrowdSec Network.
- 2025-04-07: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2024-20439 for the first time.
- 2025-04-21: CISA Remediation Deadline. Expiration of the CISA remediation deadline as described in [BOD 22-01](https://www.cisa.gov/news-events/directives/bod-22-01-reducing-significant-risk-known-exploited-vulnerabilities).

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cslu-7gHMzWmw
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2024/CVE-2024-20439.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2024-20439) follows observed exploitation activity for CVE-2024-20439. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.