CVE-2024-42741 in X5000r
Summary
by MITRE • 08/12/2024
In TOTOLINK X5000r v9.1.0cu.2350_b20230313, the file /cgi-bin/cstecgi.cgi contains an OS command injection vulnerability in setL2tpServerCfg. Authenicated Attackers can send malicious packet to execute arbitary commands.
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Analysis
by VulDB Data Team • 08/13/2024
The vulnerability identified as CVE-2024-42741 affects the TOTOLINK X5000r router firmware version v9.1.0cu.2350_b20230313 and represents a critical operating system command injection flaw within the device's web interface. This vulnerability exists in the cstecgi.cgi script at the setL2tpServerCfg function, which processes user input without proper sanitization or validation. The flaw allows authenticated attackers to inject malicious operating system commands through crafted HTTP requests, potentially enabling full system compromise. The vulnerability is particularly concerning because it requires only authentication credentials to exploit, making it accessible to anyone with legitimate access to the device's management interface. The affected component is part of the Layer 2 Tunneling Protocol server configuration functionality, which suggests that attackers could manipulate network tunneling parameters to gain unauthorized access to internal network resources.
The technical exploitation of this vulnerability occurs through the manipulation of input parameters sent to the setL2tpServerCfg function within the cstecgi.cgi script. When an authenticated user submits a request containing malicious command injection payloads, the system fails to properly validate or sanitize the input before processing it as part of an operating system command. This allows attackers to append additional commands that execute with the privileges of the web server process, typically running with elevated permissions on the device. The vulnerability stems from improper input validation practices and lacks proper command escaping or filtering mechanisms that would prevent arbitrary code execution. This type of flaw is classified as CWE-77 in the Common Weakness Enumeration catalog, specifically representing "Command Injection" where user-supplied data is directly incorporated into system commands without adequate sanitization.
The operational impact of this vulnerability extends beyond simple command execution, as it provides attackers with potential access to critical system functions and data within the router's environment. Successful exploitation could enable attackers to modify network configurations, establish persistent backdoors, access internal network resources, or even compromise other devices connected to the same network segment. The authenticated nature of the attack means that attackers do not need to perform complex network reconnaissance or credential harvesting, as they can leverage legitimate administrative access to execute malicious commands. This vulnerability significantly undermines the security posture of networks relying on affected TOTOLINK devices, as it allows for privilege escalation and persistent access to network infrastructure. The attack surface includes potential data exfiltration, network disruption, and the establishment of command and control channels that could be used for further attacks.
Mitigation strategies for CVE-2024-42741 should focus on immediate firmware updates from TOTOLINK, as the vendor has likely released patches addressing this vulnerability. Organizations should also implement network segmentation to limit access to administrative interfaces and enforce strict access controls for router management. Network monitoring solutions should be configured to detect unusual command execution patterns or anomalous traffic to the cstecgi.cgi endpoint. Security teams should conduct thorough network audits to identify all affected devices and ensure proper patch management procedures are in place. The vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, and potentially T1566 for Phishing, as attackers may leverage legitimate administrative access to execute malicious commands. Additional defensive measures include implementing web application firewalls to filter suspicious input patterns and conducting regular security assessments to identify similar command injection vulnerabilities in other network devices and applications.