CVE-2025-7551 in FH1201
Summary
by MITRE • 07/14/2025
A vulnerability was found in Tenda FH1201 1.2.0.14(408). It has been declared as critical. Affected by this vulnerability is the function fromPptpUserAdd of the file /goform/PPTPDClient. The manipulation of the argument modino/username leads to stack-based buffer overflow. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 07/14/2025
The vulnerability identified as CVE-2025-7551 represents a critical stack-based buffer overflow flaw in the Tenda FH1201 router firmware version 1.2.0.14(408). This issue resides within the PPTPDClient component, specifically in the fromPptpUserAdd function located at the /goform/PPTPDClient file path. The vulnerability stems from inadequate input validation when processing the modino/username argument, creating a condition where maliciously crafted input can exceed the bounds of a fixed-length stack buffer. The attack vector is remote, meaning an attacker can exploit this vulnerability without requiring physical access to the device, making it particularly dangerous in networked environments where routers serve as critical infrastructure components.
The technical exploitation of this buffer overflow vulnerability follows established patterns that align with CWE-121 Stack-based Buffer Overflow, which is classified under the broader category of CWE-787 Out-of-bounds Write. The flaw enables an attacker to overwrite adjacent stack memory locations, potentially leading to arbitrary code execution or system crashes. Given that the vulnerability is publicly disclosed and an exploit exists, the risk assessment is elevated beyond typical vulnerabilities, as the attack surface is immediately actionable. The PPTPDClient functionality suggests this relates to Point-to-Point Tunneling Protocol client configuration, which could provide attackers with unauthorized access to network resources or enable them to manipulate routing configurations.
The operational impact of this vulnerability extends beyond simple exploitation, as it affects the core network infrastructure security of affected Tenda FH1201 devices. Attackers could leverage this flaw to gain persistent access to network segments, potentially establishing backdoors or executing malicious code with the privileges of the affected service. The remote attack capability means that this vulnerability could be exploited from anywhere on the internet, making it particularly concerning for enterprise networks, home users with exposed routers, and organizations relying on these devices for network connectivity. From an attack framework perspective, this vulnerability would likely map to multiple ATT&CK techniques including T1059 Command and Scripting Interpreter and T1071 Application Layer Protocol, as attackers could use the compromised device as a pivot point for further network reconnaissance and lateral movement.
Mitigation strategies for CVE-2025-7551 must prioritize immediate firmware updates from Tenda, as the vendor should release patches addressing the buffer overflow in the PPTPDClient implementation. Network administrators should implement network segmentation to limit exposure of affected devices to critical systems, while also monitoring for unusual network traffic patterns that might indicate exploitation attempts. The principle of least privilege should be enforced by restricting access to the PPTPDClient interface to only authorized personnel, and implementing firewall rules to block external access to the affected device's management interfaces. Additionally, organizations should consider deploying intrusion detection systems that can identify exploitation attempts targeting known buffer overflow patterns, and maintain detailed network monitoring logs to detect unauthorized access attempts to the affected router components.