Cyber Resilience

CVE-2025-8131

HighPublic PoC

Published: 25 July 2025

Published
25 July 2025
Modified
05 August 2025
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 0.0121 79.4th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-8131 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Tenda Ac20 Firmware. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 20.6% 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).

Deeper analysis

A stack-based buffer overflow vulnerability, tracked as CVE-2025-8131 and also referenced under CWE-119 and CWE-121, affects the Tenda AC20 wireless router running firmware 16.03.08.05. The flaw resides in an unknown function of the /goform/SetStaticRouteCfg endpoint, where unsanitized input supplied to the list argument can corrupt the stack.

An authenticated remote attacker can send a specially crafted HTTP request to the management interface to trigger the overflow. Successful exploitation may allow arbitrary code execution, full device compromise, or denial of service, consistent with the CVSS 4.0 vector AV:N/AC:L/AT:N/PR:L/UI:N and the high impact metrics on confidentiality, integrity, and availability.

Public proof-of-concept code has been published, yet the EPSS score has remained flat at 0.0121 with no material rise since disclosure. Available references point to a GitHub report, VulDB entries, and the vendor site but contain no details on patches or mitigation steps.

EU & UK References

Vulnerability details

A vulnerability was found in Tenda AC20 16.03.08.05. It has been declared as critical. Affected by this vulnerability is an unknown functionality of the file /goform/SetStaticRouteCfg. The manipulation of the argument list leads to stack-based buffer overflow. The attack can…

more

be launched remotely. The exploit has been disclosed to the public and may be used.

CWE(s)

Related Threats

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.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Why these techniques?

Remote stack-based buffer overflow in the Tenda AC20 router's web management interface (/goform/SetStaticRouteCfg) enables arbitrary code execution, facilitating exploitation of public-facing applications (T1190) and remote services (T1210).

CVEs Like This One

CVE-2025-9087Same product: Tenda Ac20
CVE-2025-9088Same product: Tenda Ac20
CVE-2025-9791Same product: Tenda Ac20
CVE-2025-9046Same product: Tenda Ac20
CVE-2025-9089Same product: Tenda Ac20
CVE-2025-14655Same product: Tenda Ac20
CVE-2025-14654Same product: Tenda Ac20
CVE-2025-8810Same product: Tenda Ac20
CVE-2025-10815Same product: Tenda Ac20
CVE-2025-11385Same product: Tenda Ac20

Affected Assets

tenda
ac20 firmware
16.03.08.05

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires validation and sanitization of argument list inputs to /goform/SetStaticRouteCfg to prevent stack-based buffer overflows from manipulated data.

prevent

Enforces memory protections such as stack canaries, ASLR, and DEP to mitigate exploitation of stack-based buffer overflows even if invalid inputs are processed.

prevent

Mandates timely flaw remediation through firmware patching to eliminate the specific buffer overflow vulnerability in Tenda AC20 v16.03.08.05.

References