Cyber intrusions detected on Cisco's Smart Licensing Utility system confirmed
A critical vulnerability, CVE-2024-20439, has been identified in the Cisco Smart Licensing Utility (CSLU), which is currently being actively exploited by threat actors. The vulnerability, disclosed and patched in September 2024, allows unauthenticated remote access to vulnerable Cisco devices due to the use of hard-coded credentials[3][5].
Security researcher Nicholas Starke published a blog post in September, revealing technical details about CVE-2024-20439, including the static credential. This potentially gave any unauthorized user the ability to discover the static credential and use it to access Cisco products running the Smart Licensing Utility[6].
On March 19, 2025, exploitation attempts against CVE-2024-20439 were first observed by Johannes Ullrich of the SANS Internet Storm Center. The exploitation activity surged in mid-March, according to Ulrich[7]. However, the observed activity has been limited to attacks from a botnet over the last two weeks[8].
Ulrich believes his initial report contributed to CISA adding CVE-2024-20439 to the Known Exploited Vulnerabilities (KEV) catalog[4]. Cisco also confirmed exploitation attempts on CVE-2024-20439 in an updated security advisory[9].
It's important to note that while CVE-2024-20439 is being actively exploited, there is no specific information available indicating that it has been weaponized in ransomware attacks. However, given the nature of the vulnerability and its potential for unauthenticated remote attacks, it's deemed likely that CVE-2024-20439 could be exploited further[2].
To protect against exploitation, users are advised to ensure they are running the latest version of the affected software. The CSLU must be actively running for the flaw to be exploited, so keeping it up-to-date is crucial.
In a related development, another vulnerability, CVE-2024-20440, was disclosed and patched alongside CVE-2024-20439[1]. No new activity for these scans has been observed since Ulrich's last report[8].
As always, vigilance and prompt action are key in maintaining the security of digital infrastructure. Users are encouraged to stay informed about the latest security updates and take necessary precautions to protect their systems.
- In light of the ongoing exploitation of CVE-2024-20439, it's essential for users to implement incident response strategies, especially in the field of cybersecurity, to ensure prompt detection and mitigation of any breaches related to this vulnerability.
- The identification of CVE-2024-20439 has highlighted the importance of data-and-cloud-computing security, as the vulnerability can potentially expose sensitive information when exploited, emphasizing the need for robust cybersecurity measures.
- With the growing potential for further exploitation of CVE-2024-20439 and the possibility of its use in ransomware attacks, it's crucial to prioritize technology updates and patches, especially for systems using the Smart Licensing Utility, to reduce the risk of future incidents.
