Cyber Posture

CVE-2025-9779

High

Published: 01 September 2025

Published
01 September 2025
Modified
04 September 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 0.0029 52.8th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-9779 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 47.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

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

prevent

Directly validates the ip6addr argument in the formFilter function to prevent buffer overflow from invalid input manipulation.

preventrecover

Requires timely remediation of the identified buffer overflow flaw via firmware patching to eliminate the vulnerability.

prevent

Provides memory protections such as stack canaries, ASLR, and DEP to mitigate successful buffer overflow exploitation leading to code execution.

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 public web form (/boafrm/formFilter) on network-exposed router enables remote exploitation of public-facing application for arbitrary code execution.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

A vulnerability was detected in TOTOLINK A702R 4.0.0-B20211108.1423. Affected by this vulnerability is the function sub_4162DC of the file /boafrm/formFilter. The manipulation of the argument ip6addr results in buffer overflow. It is possible to launch the attack remotely. The exploit…

more

is now public and may be used.

Deeper analysisAI

CVE-2025-9779 is a buffer overflow vulnerability (CWE-119, CWE-120) in the TOTOLINK A702R router firmware version 4.0.0-B20211108.1423. The flaw affects the sub_4162DC function in the /boafrm/formFilter file, where manipulation of the ip6addr argument triggers the overflow. Published on 2025-09-01, it carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

Remote attackers with low privileges can exploit this vulnerability over the network with low complexity and no user interaction required. Exploitation leads to high impacts on confidentiality, integrity, and availability, potentially enabling arbitrary code execution or system compromise on the affected router.

References point to a public proof-of-concept exploit on GitHub, including detailed exploitation steps, as well as VulDB entries documenting the issue. No vendor advisories or patches are specified in the available information.

The exploit is public and available for use, heightening the risk of real-world attacks against unpatched TOTOLINK A702R devices.

Details

CWE(s)

Affected Products

totolink
a702r firmware
4.0.0-b20211108.1423

CVEs Like This One

CVE-2025-9780Same product: Totolink A702R
CVE-2025-9783Same product: Totolink A702R
CVE-2025-8139Same product: Totolink A702R
CVE-2025-8138Same product: Totolink A702R
CVE-2025-8136Same product: Totolink A702R
CVE-2025-9781Same product: Totolink A702R
CVE-2025-8137Same product: Totolink A702R
CVE-2025-8140Same product: Totolink A702R
CVE-2025-9782Same product: Totolink A702R
CVE-2025-9303Same vendor: Totolink

References