CVE-2025-4269 in A720R
Summary
by MITRE • 05/05/2025
A vulnerability was found in TOTOLINK A720R 4.1.5cu.374 and classified as critical. This issue affects some unknown processing of the file /cgi-bin/cstecgi.cgi of the component Log Handler. The manipulation of the argument topicurl with the input clearDiagnosisLog/clearSyslog/clearTracerouteLog leads to improper access controls. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 05/05/2025
The vulnerability identified as CVE-2025-4269 represents a critical security flaw in the TOTOLINK A720R router firmware version 4.1.5cu.374, specifically within the Log Handler component of the web interface. This issue resides in the /cgi-bin/cstecgi.cgi file which processes administrative requests through the web management interface. The vulnerability stems from inadequate input validation and access control mechanisms that fail to properly authenticate and authorize administrative operations, creating a significant attack surface for malicious actors.
The technical flaw manifests when processing the topicurl parameter within the Log Handler functionality. Attackers can manipulate this parameter by injecting specific values such as clearDiagnosisLog, clearSyslog, or clearTracerouteLog to execute unauthorized administrative operations. This represents a classic improper access control vulnerability that allows privilege escalation and unauthorized modification of system logging configurations. The flaw operates at the application layer and specifically targets the router's administrative interface, making it particularly dangerous as it can be exploited without requiring physical access to the device.
The operational impact of this vulnerability is severe as it enables remote attackers to compromise the router's logging capabilities and potentially gain unauthorized access to sensitive system information. The ability to clear system logs, diagnosis logs, and traceroute logs can be used to cover malicious activities while simultaneously disrupting network monitoring and forensic analysis capabilities. This vulnerability directly violates the principle of least privilege and undermines the router's security posture, potentially allowing attackers to establish persistent access or conduct further reconnaissance activities.
This vulnerability aligns with CWE-285, which addresses improper access control issues in software applications. The flaw also maps to ATT&CK technique T1078 which covers valid accounts and T1566 which covers credential harvesting, as the vulnerability enables unauthorized access to administrative functions without proper authentication. The public disclosure of exploitation methods further increases the risk profile, as it provides attackers with readily available techniques to compromise affected devices. Organizations should consider implementing network segmentation and monitoring for unusual log clearing activities as defensive measures against this vulnerability.
The exploitation of this vulnerability requires no specialized tools beyond standard web browsing capabilities, making it accessible to threat actors of varying skill levels. The remote attack vector eliminates the need for physical access to the device, significantly expanding the potential attack surface. Given that many network administrators rely on router logging for security monitoring and incident response, the ability to clear these logs creates a dangerous situation where malicious activities can remain undetected for extended periods. This vulnerability represents a critical weakness in the router's administrative security model and requires immediate attention through firmware updates or network-level mitigations to prevent potential compromise of entire network infrastructures.