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CVE-2021-20166 (GCVE-0-2021-20166)

Vulnerability from cvelistv5 – Published: 2021-12-30 21:31 – Updated: 2024-08-03 17:30
VLAI Shadowserver Previdian
Summary
Netgear RAX43 version 1.0.3.96 contains a buffer overrun vulnerability. The URL parsing functionality in the cgi-bin endpoint of the router containers a buffer overrun issue that can redirection control flow of the applicaiton.
Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
  • Buffer Overrun
Assigner
References
Impacted products
Vendor Product Version CPE status
n/a Netgear RAX43 Affected: 1.0.3.96
Shadowserver
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 4cafea93-f511-497d-854e-10216ad69a00

Vulnerability ID: CVE-2021-20166

Status: Confirmed

Status Updated: 2026-09-06 00:00 UTC

Exploited: Yes

Characteristics
Severity: 88.0
Timestamps
First Seen: 2023-10-14
Asserted: 2023-10-14
Last Seen: 2026-09-06
Scope
Asset Exposure: ['internet-facing']
Notes: Affected: NETGEAR / RAX43 | Class: router | Severity: High (CVSS 8.8) | IoT: yes | In CISA KEV: no | Honeypot connections on 2026-09-06: 55
Evidence

Type: Honeypot

Signal: In The Wild Attempts

Confidence: 70%

Source: shadowserver

Details
1D 3
Iot yes
Feed Shadowserver Foundation honeypot/exploited-vulnerabilities
Type http-scan
Class router
7D Avg 2
Vendor NETGEAR
30D Avg 1
90D Avg 1
Product RAX43
Cisa Kev no
Connections 55
Observation Date 2026-09-06
Vulnerability Class CVSS
Vulnerability Score 8.8
Vulnerability Severity High
References
Created: 2026-07-01 07:17 UTC | Updated: 2026-09-08 01:00 UTC
Previdian
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: b325b9f4-ca8e-4569-9e41-2566ca4697d7

Vulnerability ID: CVE-2021-20166

Status: Confirmed

Status Updated: 2026-06-07 00:00 UTC

Exploited: Yes

Timestamps
First Seen: 2026-06-07
Asserted: 2026-06-07
Scope
Notes: KEVIntel entry: Netgear RAX43 version 1.0.3.96 contains a buffer overrun vulnerability. The URL parsing functionality in the cgi-bin endpoint of the router... | Affected: Netgear / RAX43 | CVSS: 8.8 (HIGH) | EPSS: 0.02177 | Used in malware: unknown | Not yet in CISA KEV: True
Evidence

Type: Public Report

Signal: Successful Exploitation

Confidence: 70%

Source: kevintel

Details
Feed KEVIntel (kevintel.com)
Title Netgear RAX43 version 1.0.3.96 contains a buffer overrun vulnerability. The URL parsing functionality in the cgi-bin endpoint of the router...
Vendor Netgear
Product RAX43
Added Date 2026-06-07T00:00:00.000Z
Cvss Score 8.8
Epss Score 0.02177
Cvss Severity HIGH
Epss Percentile 0.79988
Used In Malware unknown
Ahead Of Cisa Kev None
Not Yet In Cisa Kev True
References
Created: 2026-06-19 12:42 UTC | Updated: 2026-06-19 12:42 UTC
Show details on NVD website
To clipboard 

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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.
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  • 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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