EUVD-2025-18267CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
4Description
Buffer Overflow vulnerability in TOTOLINK N600R v4.3.0cu.7866_B2022506 allows a remote attacker to execute arbitrary code via the UPLOAD_FILENAME component
Analysis
Critical remote code execution vulnerability in TOTOLINK N600R router firmware v4.3.0cu.7866_B2022506, exploitable through a buffer overflow in the UPLOAD_FILENAME parameter without authentication. An unauthenticated remote attacker can execute arbitrary code with no user interaction required, achieving complete system compromise with CVSS 9.8 severity. KEV status and active exploitation data unavailable from provided sources; EPSS probability should be assumed high given unauthenticated network attack vector and critical impact.
Technical Context
The vulnerability exists in the file upload handling mechanism of the TOTOLINK N600R wireless router firmware. The root cause is a classic CWE-120 (Buffer Copy without Checking Size of Input) condition in the UPLOAD_FILENAME parameter processing—the firmware fails to validate or bound-check user-supplied filename input before copying it into a fixed-size stack or heap buffer. TOTOLINK N600R is a consumer-grade 600Mbps WiFi router; the vulnerable component likely resides in the web-based administration interface or firmware update subsystem. The attack leverages HTTP POST/multipart requests to the upload endpoint, allowing attackers to overflow the buffer and overwrite adjacent memory containing return addresses or function pointers, enabling arbitrary code execution within the router's privileged context.
Affected Products
- product: TOTOLINK N600R; version: v4.3.0cu.7866_B2022506; affected_component: UPLOAD_FILENAME parameter in firmware update/file upload module; cpe: cpe:2.3:o:totolink:n600r_firmware:4.3.0cu.7866_b2022506:*:*:*:*:*:*:*; attack_vector: Remote (unauthenticated HTTP request); notes: Earlier versions may be affected; verify with vendor. Patched versions unknown from provided data—check TOTOLINK security advisories.
Remediation
Upgrade TOTOLINK N600R firmware to patched version (version number not provided in sources—contact TOTOLINK support or check official firmware download page at totolink.net for N600R security updates post-2025); priority: CRITICAL - apply immediately Workaround (Temporary): Restrict WAN access to the router's web interface via firewall rules; disable remote administration if enabled; isolate router from untrusted networks pending patch availability; priority: HIGH - implement until patch is available Detection: Monitor router logs for unusual HTTP POST requests to upload endpoints with oversized or malformed UPLOAD_FILENAME parameters; inspect network traffic for suspicious firmware update attempts; priority: MEDIUM Vendor Contact: Check TOTOLINK's official security advisory and firmware download portal (https://www.totolink.net) for N600R patch releases; priority: CRITICAL
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External POC / Exploit Code
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