CVE-2025-5909 in EX1200T
Summary
by MITRE • 06/10/2025
A vulnerability, which was classified as critical, was found in TOTOLINK EX1200T up to 4.1.2cu.5232_B20210713. Affected is an unknown function of the file /boafrm/formReflashClientTbl of the component HTTP POST Request Handler. The manipulation leads to buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 06/16/2025
The vulnerability identified as CVE-2025-5909 represents a critical buffer overflow flaw within the TOTOLINK EX1200T router firmware version 4.1.2cu.5232_B20210713 and earlier. This security weakness resides in the HTTP POST Request Handler component, specifically within the /boafrm/formReflashClientTbl file, making it accessible through network-based attacks. The buffer overflow vulnerability occurs when the device processes incoming HTTP POST requests without adequate input validation, allowing malicious actors to craft specially crafted payloads that exceed the allocated buffer space. This critical flaw enables remote code execution capabilities, as attackers can manipulate the device's memory through carefully constructed input data, potentially leading to complete system compromise and unauthorized access to the network infrastructure.
The technical exploitation of this vulnerability follows the ATT&CK framework's T1210 technique for exploiting vulnerabilities in network infrastructure devices, specifically targeting the network infrastructure category. The flaw manifests as a classic buffer overflow condition where insufficient bounds checking occurs during HTTP request processing, allowing attackers to overwrite adjacent memory locations. This type of vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The vulnerability's remote attack surface means that no physical access or local network credentials are required to exploit the flaw, making it particularly dangerous for enterprise and residential network environments. The exposed HTTP POST handler interface provides an accessible attack vector that can be leveraged by threat actors without requiring specialized knowledge of the device's internal architecture.
The operational impact of CVE-2025-5909 extends beyond simple device compromise, potentially enabling attackers to establish persistent backdoors, redirect network traffic, or use the compromised device as a pivot point for further attacks within the network perimeter. This vulnerability directly affects the integrity and availability of network services, as successful exploitation can lead to complete device takeover and denial of service conditions. Network administrators face significant challenges in detecting this attack vector, as the malicious traffic may appear legitimate to standard network monitoring tools. The public disclosure of exploit code increases the likelihood of widespread exploitation across networks that have not yet applied firmware updates, creating a window of opportunity for cybercriminals to target vulnerable TOTOLINK EX1200T devices in both corporate and residential environments.
Mitigation strategies for CVE-2025-5909 require immediate firmware updates from TOTOLINK to address the buffer overflow vulnerability in the HTTP POST Request Handler component. Organizations should implement network segmentation to isolate affected devices from critical network infrastructure and apply firewall rules to restrict access to the device's HTTP management interface. Network administrators should also monitor for unusual traffic patterns that may indicate exploitation attempts and consider implementing intrusion detection systems with signatures specific to this vulnerability. The recommended approach aligns with industry best practices outlined in the NIST Cybersecurity Framework, particularly focusing on the Identify and Protect functions. Additional defensive measures include disabling unnecessary services, implementing strong authentication mechanisms, and maintaining detailed network logs to detect potential exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to identify similar vulnerabilities in other network infrastructure devices and ensure comprehensive network security posture maintenance.