Cyber Resilience

CVE-2025-6734

HighPublic PoC

Published: 26 June 2025

Published
26 June 2025
Modified
08 January 2026
KEV Added
Patch
CVSS Score v4 7.4 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0149 81.5th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-6734 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Utt 840G Firmware. Its CVSS base score is 7.4 (High).

Operationally, ranked in the top 18.5% 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 buffer overflow vulnerability exists in the UTT HiPER 840G router firmware up to version 3.1.1-190328. The flaw resides in the sub_484E40 function within the /goform/formP2PLimitConfig API endpoint, where improper handling of the "except" argument allows an attacker to overflow a buffer. The issue is tracked under CWE-119 and CWE-120 and carries a CVSS 4.0 score of 7.4.

An authenticated remote attacker can send a crafted request to the affected endpoint to trigger the overflow. Successful exploitation grants the ability to execute arbitrary code or crash the device, with a publicly available proof-of-concept demonstrating the attack vector.

The vendor was notified prior to disclosure but has not issued a response or patch. Public references include exploit code and vulnerability database entries, yet no official mitigation guidance is available.

The EPSS score remains flat at 0.0149 with no material increase since publication, indicating limited observed exploitation interest to date.

EU & UK References

Vulnerability details

A vulnerability was found in UTT HiPER 840G up to 3.1.1-190328. It has been rated as critical. This issue affects the function sub_484E40 of the file /goform/formP2PLimitConfig of the component API. The manipulation of the argument except leads to buffer…

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overflow. The attack may be 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

utt
840g firmware
≤ 3.1.1-190328

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.

addresses: CWE-119 CWE-120

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

References