CVE-2021-27257

Original summary

Normalized public record · Updated Nov 3, 2026

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.

Publisher and source text is retained separately from QFinch interpretation.

Affected products

Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.

Remediation

Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.

1. Confirm the affected product and reachable code path exist in your environment.
2. Apply the vendor-supported patch or mitigation from the primary advisory.
3. Rescan the exact deployed revision and retain verification evidence.

Evidence coverage

SSVC priority

LOW

Confidence

Not available

Aliases

None reported

Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.

Sources and record history

1. kb.netgear.com ↗
2. www.zerodayinitiative.com ↗

Record history

Published Mar 5, 2021 · Last refreshed Nov 3, 2026