CVE-2021-31755 kev in the critical feed json
An issue was discovered on Tenda AC11 devices with firmware through 02.03.01.104_CN.
published 2021-05-07 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18639
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Exploited
- added 2021-11-03
- epss
- 86.5%
- EPSS 86.5% chance of exploitation in 30 days, percentile 99.7%
- public exploits
- 0
- none known, plus a Nuclei check
Summary
An issue was discovered on Tenda AC11 devices with firmware through 02.03.01.104_CN. A stack buffer overflow vulnerability in /goform/setmac allows attackers to execute arbitrary code on the system via a crafted post request.
Patch / fix
cisa required action Apply updates per vendor instructions.
Timeline
- Published
- Added to CISA KEV
- CISA patch deadline
- CISA SSVC: exploitation active
Known exploited
- Added
- 5 y ago
- Patch by
- 2021-11-17 (4 y ago)
- Ransomware
- Not known
- Required action
- Apply updates per vendor instructions.
- Vendor, product
- Tenda, AC11 Router
- CISA name
- Tenda AC11 Router Stack Buffer Overflow Vulnerability
CISA SSVC
- Exploitation
- Active, exploited in the wild
- Automatable
- yes
- Technical impact
- total
- Assessed
- 21 mo ago
Exploit prediction
86.51% chance of exploitation in the next 30 days, higher than 99.7% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- Nuclei template Tenda Router AC11 - Remote Command Injection nuclei detection template
- github.com https://github.com/Yu3H0/IoT_CVE/tree/main/Tenda/CVE_3 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 10.0 | AV:N/AC:L/Au:N/C:C/I:C/A:C |
Classification
- Weakness
-
- CWE-787 Out-of-bounds Write
References
-
github.com
/Yu3H0/IoT_CVE/tree/main/Tenda/CVE_3
broken-link, exploit, issue-tracking, third-party-advisory
-
cisa.gov
/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31755
government-resource, us-government-resource
Sources
- CVE List CVE-2021-31755
- NVD CVE-2021-31755
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