Which versions of Ac20 Firmware are affected by CVE-2025-9791?

Organizations using A weakness face moderate risk from CVE-2025-9791, a buffer overflow vulnerability rated CVSS 7.4.

Is there a public PoC exploit available for CVE-2025-9791?

Yes, a public proof-of-concept exploit is available for CVE-2025-9791. Prioritise patching immediately. EPSS: 0.4%.

How to fix or mitigate CVE-2025-9791?

Within 7 days: Identify all affected systems and apply vendor patches promptly. Monitor vendor channels for patch availability.

Ac20 Firmware CVE-2025-9791

Q: What is the CVSS score of CVE-2025-9791?

CVE-2025-9791 has a CVSS 4.0 base score of 7.4 (High). CVSS vector: 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 exploitation probability: 0.4%.

HIGH

Buffer Overflow (CWE-119)

2025-09-01 cna@vuldb.com

Buffer Overflow Tenda Ac20 Firmware

7.4

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

7.4 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 19:09 vuln.today

PoC Detected

Sep 04, 2025 - 16:20 vuln.today

Public exploit code

CVE Published

Sep 01, 2025 - 19:15 nvd

HIGH 7.4

DescriptionCVE.org

A weakness has been identified in Tenda AC20 16.03.08.05. This vulnerability affects unknown code of the file /goform/fromAdvSetMacMtuWan. This manipulation of the argument wanMTU causes stack-based buffer overflow. Remote exploitation of the attack is possible. The exploit has been made available to the public and could be exploited.

AnalysisAI

A weakness has been identified in Tenda AC20 16.03.08.05. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Buffer Overflow (CWE-119), which allows attackers to corrupt memory to execute arbitrary code or crash the application. A weakness has been identified in Tenda AC20 16.03.08.05. This vulnerability affects unknown code of the file /goform/fromAdvSetMacMtuWan. This manipulation of the argument wanMTU causes stack-based buffer overflow. Remote exploitation of the attack is possible. The exploit has been made available to the public and could be exploited. Affected products include: Tenda Ac20 Firmware.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Use memory-safe languages or bounds-checking. Enable ASLR, DEP/NX, stack canaries. Use safe string functions.