CVE-2021-27691 (GCVE-0-2021-27691)

Vulnerability from cvelistv5 – Published: 2021-04-15 23:14 – Updated: 2024-08-03 21:26
VLAI Previdian
Summary
Command Injection in Tenda G0 routers with firmware versions v15.11.0.6(9039)_CN and v15.11.0.5(5876)_CN , and Tenda G1 and G3 routers with firmware versions v15.11.0.17(9502)_CN or v15.11.0.16(9024)_CN allows remote attackers to execute arbitrary OS commands via a crafted action/setDebugCfg request. This occurs because the "formSetDebugCfg" function executes glibc's system function with untrusted input.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
  • n/a
Assigner
References
Previdian
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: b276ca61-525a-4315-9470-c2ab78a667ae

Vulnerability ID: CVE-2021-27691

Status: Confirmed

Status Updated: 2026-08-22 02:00 CEST

Exploited: Yes

Timestamps
First Seen: 2026-08-22
Asserted: 2026-08-22
Scope
Notes: Command Injection in Tenda G0 routers with firmware versions v15.11.0.6(9039)_CN and v15.11.0.5(5876)_CN , and Tenda G1 and G3 routers with... | Affected: Tenda / G0, G1, G3 routers | CVSS: 9.8 (CRITICAL) | EPSS: 0.25183 | Used in malware: unknown | Not yet in CISA KEV: True
Evidence

Type: Public Report

Signal: Successful Exploitation

Confidence: 70%

Source: previdian

Details
Feed Previdian (previdian.com)
Title Command Injection in Tenda G0 routers with firmware versions v15.11.0.6(9039)_CN and v15.11.0.5(5876)_CN , and Tenda G1 and G3 routers with...
Cve Id CVE-2021-27691
Vendor Tenda
Ghsa Id None
Product G0, G1, G3 routers
Added Date 2026-08-22T00:00:00.000Z
Cvss Score 9.8
Epss Score 0.25183
Previous Ids
Cvss Severity CRITICAL
Virtual Patch False
Cvss Estimated False
Epss Percentile 0.97874
Used In Malware unknown
Vulnerability Id CVE-2021-27691
Ahead Of Cisa Kev None
Not Yet In Cisa Kev True
References
Created: 2026-10-02 09:09 CEST | Updated: 2026-10-02 09:09 CEST
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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