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Vulnerability record · CVE-2021-27257 · published 5 March 2021

CVE-2021-27257: Netgear br200 firmware improper certificate validation vulnerability

Netgear · Br200 Firmware

This vulnerability allows network-adjacent attackers to compromise the integrity of downloaded information on affected installations of NETGEAR R7800 firmware version 1.0.2.76. Authentication is not required to exploit this vulnerability. The specific flaw exists within the downloading of files via FTP. The issue results from the lack of proper validation of the certificate presented by the server. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-12362.

6.5 CVSS 3.1 Medium EPSS 0.32% · top 76.9% CWE-295 · Improper certificate validation
6.5CVSS 3.1 base score, v2 3.3
0.32%EPSS exploitation probability, 30 days
NoNot in CISA KEV
43Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

Description

This vulnerability allows network-adjacent attackers to compromise the integrity of downloaded information on affected installations of NETGEAR R7800 firmware version 1.0.2.76. Authentication is not required to exploit this vulnerability. The specific flaw exists within the downloading of files via FTP. The issue results from the lack of proper validation of the certificate presented by the server. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-12362.

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

43 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders PatchVendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-264/ Third Party AdvisoryVDB Entry
https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders PatchVendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-264/ Third Party AdvisoryVDB Entry

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-27257), CISA KEV, FIRST EPSS (scores of 2026-10-05). This page is refreshed as NVD updates the record.