CVE-2025-3663
Published: 16 April 2025
Summary
CVE-2025-3663 is a medium-severity Incorrect Privilege Assignment (CWE-266) vulnerability in Totolink A3700R Firmware. Its CVSS base score is 6.9 (Medium).
Operationally, ranked in the top 15.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Deeper analysis
A critical improper access control vulnerability tracked as CVE-2025-3663 affects the TOTOLINK A3700R router running firmware 9.1.2u.5822_B20200513. The issue is located in the setWiFiEasyCfg and setWiFiEasyGuestCfg functions of the Password Handler component inside /cgi-bin/cstecgi.cgi, where manipulation of inputs bypasses intended restrictions.
Remote attackers without authentication can exploit the flaw to alter WiFi configuration settings. Public proof-of-concept code has been released, enabling unauthenticated parties to trigger the weakness over the network.
Vendor contact prior to disclosure yielded no response, and available references contain no mitigation guidance or firmware updates. The associated EPSS score shows only a modest peak of 0.0279 against a current value of 0.0215.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-11470
Vulnerability details
A vulnerability, which was classified as critical, has been found in TOTOLINK A3700R 9.1.2u.5822_B20200513. This issue affects the function setWiFiEasyCfg/setWiFiEasyGuestCfg of the file /cgi-bin/cstecgi.cgi of the component Password Handler. The manipulation leads to improper access controls. The attack may be…
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initiated remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.
Supervision and review of access control activities directly detects and remediates improper access configurations or usages.
Defining account types, requiring approvals for creation, specifying authorizations, monitoring usage, and reviewing accounts directly prevents improper access control by ensuring only authorized accounts exist and are used.
The control requires explicit definition of separated access authorizations, making incorrect privilege assignments that bundle conflicting duties harder to implement.
Ensures privileges are assigned only as necessary rather than incorrectly over-granted.
Device lock enforces restricted access until re-authentication, directly reducing unauthorized use of active sessions.
Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.
By automatically labeling outputs with security attributes, the control supports attribute-based enforcement and reduces exploitability of improper access control weaknesses.