Cyber Posture

CVE-2025-51630

CriticalPublic PoC

Published: 17 July 2025

Published
17 July 2025
Modified
18 July 2025
KEV Added
Patch
CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0025 47.9th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-51630 is a critical-severity Classic Buffer Overflow (CWE-120) vulnerability in Totolink N350Rt Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 47.9th percentile by exploit likelihood (below the median); 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).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

preventrecover

Directly remediates the buffer overflow vulnerability in the setIpPortFilterRules function through flaw identification, patching, and firmware updates.

prevent

Enforces validation of the ePort parameter at the input interface to prevent buffer overflows from insufficient bounds checking on excessive data.

prevent

Implements memory protections such as stack canaries and non-executable memory to mitigate arbitrary code execution from buffer overflow exploitation.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Buffer overflow in the web management function setIpPortFilterRules of the TOTOLINK N350RT router enables remote exploitation of a public-facing application.

NVD Description

TOTOLINK N350RT V9.3.5u.6139_B20201216 was discovered to contain a buffer overflow via the ePort parameter in the function setIpPortFilterRules.

Deeper analysisAI

CVE-2025-51630 is a buffer overflow vulnerability (CWE-120) affecting the TOTOLINK N350RT router running firmware version V9.3.5u.6139_B20201216. The flaw occurs in the setIpPortFilterRules function when processing the ePort parameter, allowing excessive data to overflow buffers due to insufficient input validation. It has a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity with high impacts on confidentiality, integrity, and availability.

The vulnerability can be exploited remotely by unauthenticated attackers with network access and no user interaction required. By sending a specially crafted request targeting the ePort parameter, an attacker can trigger the buffer overflow, potentially leading to arbitrary code execution, denial of service, or full compromise of the device.

References point to a GitHub repository detailing the vulnerability and including proof-of-concept information for the ePort issue, but no official advisories, patches, or mitigation guidance from the vendor are provided in the available sources.

Details

CWE(s)

Affected Products

totolink
n350rt firmware
9.3.5u.6139_b20201216

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References