Is CVE-2021-31755 actively exploited?

Yes. CVE-2021-31755 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2021-31755 be exploited remotely?

The attack vector of CVE-2021-31755 has not been classified yet.

What is the CVSS score of CVE-2021-31755?

CVE-2021-31755 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2021-31755

HIGHCISA KEVIN THE WILD

CVE-2021-31755

Published: November 3, 2021

EPSS:94.26%probability of exploitation in 30 daysPercentile:99.9th

Official Description

Tenda AC11 devices contain a stack buffer overflow vulnerability in /goform/setmac which allows attackers to execute code via a crafted post request.

NVD Source

CISA KEV Advisory

Tenda AC11 Router Stack Buffer Overflow Vulnerability

Tenda AC11 devices contain a stack buffer overflow vulnerability in /goform/setmac which allows attackers to execute code via a crafted post request.

Added to KEV: 2021-11-03Federal patch deadline: 2021-11-17

Required Action (CISA)

Apply updates per vendor instructions.

Risk Analysis

This vulnerability in Tenda AC11 devices is a stack buffer overflow, which means an attacker can send too much data to a specific function, overwriting memory and potentially executing their own code. The high EPSS score of 0.94261 indicates a very high probability of exploitation, and its presence in the KEV confirms it is actively exploited.

This vulnerability is actively exploited in the wild, meaning that functional exploits are publicly available and being used by threat actors. Attackers can exploit this remotely via crafted POST requests.

Recommended Action

It is critical to update Tenda AC11 devices to the latest firmware version provided by the vendor. If updates are not available, consider isolating these devices from public networks.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-31755 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2021-31755 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.