R7800 FirmwareOperating system · Netgear

CVE-2021-45623

CRITICAL · 9.8 CVSS v3.1 Published 2021-12-26
Fix available
A fix is available. Upgrade to 1.0.2.74 / 1.0.5.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects R7800 before 1.0.2.74, R9000 before 1.0.5.2, and XR500 before 2.3.2.66.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-77

User input reaches a command interpreter without being fully separated from the command itself, so an attacker can append instructions of their own. Because those run with the application's privileges, it frequently means control of the host. The lasting fix is to avoid constructing commands from input — call APIs directly and pass arguments as data, never as concatenated strings.

General guidance for the command injection class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
R7800 FirmwareOperating system
Affected:< 1.0.2.74
R9000 FirmwareOperating system
Affected:< 1.0.5.2
Xr500 FirmwareOperating system
Affected:< 2.3.2.66

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.0.2.74 / 1.0.5.2 / 2.3.2.66 or later
Fixed in 1.0.2.741.0.5.22.3.2.66
Vendor patch kb.netgear.com →
Recommended fix High confidence

R7800: upgrade to firmware 1.0.2.74 | R9000: upgrade to firmware 1.0.5.2 | XR500: upgrade to firmware 2.3.2.66

  1. 1. Identify your NETGEAR router model (R7800, R9000, or XR500)
  2. 2. Download the corresponding fixed firmware version from NETGEAR's official support website
  3. 3. Access the router's web management interface by connecting to the router's network
  4. 4. Navigate to the Administration or Advanced settings section
  5. 5. Locate the Firmware Update option
  6. 6. Upload the downloaded firmware file and initiate the update
  7. 7. Wait for the firmware to install completely - do not power off the router
  8. 8. After installation completes, the router will automatically restart

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $3,550. Get the upgrade done

Scan for this in your stack

Free · runs locally
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Check whether your project pulls in CVE-2021-45623 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-45623 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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