CVE-2025-8140
Published: 25 July 2025
Summary
CVE-2025-8140 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Totolink A702R Firmware. Its CVSS base score is 7.4 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 19.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2025-8140 is a buffer overflow vulnerability affecting the TOTOLINK A702R router running firmware version 4.0.0-B20230721.1521. It exists in unknown code of the file /boafrm/formWlanMultipleAP within the HTTP POST Request Handler component, where manipulation of the submit-url argument triggers the flaw, classified under CWE-119 and CWE-120.
An authenticated remote attacker can exploit the issue by sending a crafted HTTP POST request to the affected endpoint, achieving high-impact outcomes including potential arbitrary code execution that compromises the confidentiality, integrity, and availability of the device. The CVSS 4.0 score of 7.4 reflects network attack vector, low complexity, and no required user interaction.
Public references include a detailed proof-of-concept on GitHub along with VulDB entries confirming the exploit has been disclosed, while the vendor site offers no specific patch or mitigation guidance in the provided information. The associated EPSS remains low and stable near 0.014 with no material increase.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-22580
Vulnerability details
A vulnerability was found in TOTOLINK A702R 4.0.0-B20230721.1521. It has been declared as critical. This vulnerability affects unknown code of the file /boafrm/formWlanMultipleAP of the component HTTP POST Request Handler. The manipulation of the argument submit-url leads to buffer overflow.…
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The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote unauthenticated buffer overflow in the router's HTTP POST handler (/boafrm/formWlanMultipleAP) enables exploitation of a public-facing web application (T1190) and remote service (T1210), facilitating potential code execution or access, and directly supports application exploitation for endpoint denial of service (T1499.004) as demonstrated by the public PoC.
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the buffer overflow flaw in the /boafrm/formWlanMultipleAP HTTP POST handler through timely patching or firmware updates.
Validates the 'submit-url' argument in HTTP POST requests to block oversized or malformed inputs that trigger the buffer overflow.
Implements memory protections like non-executable stacks and ASLR to limit arbitrary code execution even if the buffer overflow occurs.