Two critical vulnerabilities in Cisco Smart Licensing Utility (CLSU) have been actively targeted in cyberattacks. The flaws, CVE-2024-20439 and CVE-2024-20440, were patched by Cisco in September 2024 after their discovery. CVE-2024-20439 involves an undocumented static user credential that enables unauthenticated attackers to gain administrative access. CVE-2024-20440 exploits excessive verbosity in the log files, allowing attackers to access sensitive data such as API credentials.
The vulnerabilities can only be exploited if the Cisco Smart Licensing Utility is actively running. The flaws affect versions 2.0.0, 2.1.0, and 2.2.0 of the software, with version 2.3.0 being immune to these issues. Attackers can gain unauthorized access by exploiting the hardcoded password or the overly detailed log files. Although the vulnerabilities were patched in 2024, threat actors have been attempting to exploit them, as observed by SANS Internet Storm Center.
Security researchers believe these vulnerabilities were used in a broader campaign, with attackers targeting CLSU instances exposed on the internet.
The same attackers are also exploiting other vulnerabilities, including an information disclosure flaw in Guangzhou Yingke Electronic DVRs. While the exact goal of these attacks remains unclear, researchers have observed a consistent effort to access and compromise vulnerable systems.
The attack techniques suggest a sophisticated approach by the threat actors involved.
Cisco has not yet confirmed any direct reports of malicious exploitation of these vulnerabilities. However, they have urged users to apply the patches to prevent potential attacks. The company’s advisory emphasizes that these flaws are only exploitable on unpatched systems. It also notes that similar backdoor vulnerabilities have been found in Cisco products in recent years, which highlights ongoing security concerns.
