Cyber Posture

CVE-2025-8137

HighPublic PoC

Published: 25 July 2025

Published
25 July 2025
Modified
28 July 2025
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0042 61.8th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-8137 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 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 38.2% 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-16 (Memory Protection).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

SI-10 requires validation of the 'mac' argument in HTTP POST requests to /boafrm/formIpQoS, directly preventing the buffer overflow by restricting input size and format.

prevent

SI-16 implements memory protections like address space layout randomization and non-executable stacks to mitigate exploitation of the buffer overflow in the HTTP POST handler.

prevent

SI-2 ensures timely firmware updates to remediate the specific buffer overflow vulnerability in TOTOLINK A702R firmware version 4.0.0-B20230721.1521.

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.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Buffer overflow in public-facing web management interface (/boafrm/formIpQoS) enables remote exploitation for initial access (T1190) and denial-of-service via application crash (T1499.004), as demonstrated by public PoC.

NVD Description

A vulnerability has been found in TOTOLINK A702R 4.0.0-B20230721.1521 and classified as critical. Affected by this vulnerability is an unknown functionality of the file /boafrm/formIpQoS of the component HTTP POST Request Handler. The manipulation of the argument mac leads to…

more

buffer overflow. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.

Deeper analysisAI

CVE-2025-8137 is a critical buffer overflow vulnerability (CVSS 3.1 score of 8.8) affecting the TOTOLINK A702R router running firmware version 4.0.0-B20230721.1521. The issue resides in an unknown functionality of the /boafrm/formIpQoS component within the HTTP POST Request Handler, where manipulation of the "mac" argument triggers the overflow. It maps to CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-120 (Buffer Copy without Checking Size of Input).

The vulnerability enables remote exploitation by an authenticated attacker with low privileges (PR:L), requiring no user interaction and low attack complexity (AC:L) over the network (AV:N). Successful exploitation grants high impacts on confidentiality, integrity, and availability (C:H/I:H/A:H), potentially allowing arbitrary code execution or denial of service on the affected device.

Advisories from VulDB (ctiid.317533, id.317533, submit.620483) document the issue and recent submission details, while a GitHub repository (panda666-888/vuls) discloses a public proof-of-concept exploit targeting the formIpQoS endpoint. The vendor's site (totolink.net) is referenced but provides no specific patch information in available details; practitioners should check for firmware updates directly.

Details

CWE(s)

Affected Products

totolink
a702r firmware
4.0.0-b20230721.1521

CVEs Like This One

CVE-2025-8139Same product: Totolink A702R
CVE-2025-8138Same product: Totolink A702R
CVE-2025-8136Same product: Totolink A702R
CVE-2025-8140Same product: Totolink A702R
CVE-2025-9780Same product: Totolink A702R
CVE-2025-9783Same product: Totolink A702R
CVE-2025-9782Same product: Totolink A702R
CVE-2025-9779Same product: Totolink A702R
CVE-2025-9781Same product: Totolink A702R
CVE-2025-8245Same vendor: Totolink

References