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D6220 FirmwareOperating system · Netgear

CVE-2021-45638

CRITICAL · 9.8 CVSS v3.1 Published 2021-12-26
Fix available
A fix is available. Upgrade to 1.0.0.56 / 1.0.0.68 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 a stack-based buffer overflow by an unauthenticated attacker. This affects D6220 before 1.0.0.68, D6400 before 1.0.0.102, D7000v2 before 1.0.0.74, D8500 before 1.0.3.60, DC112A before 1.0.0.56, R6300v2 before 1.0.4.50, R6400 before 1.0.1.68, R7000 before 1.0.11.116, R7100LG before 1.0.0.70, RBS40V before 2.6.2.8, RBW30 before 2.6.2.2, RS400 before 1.5.1.80, R7000P before 1.3.2.132, and R6900P before 1.3.2.132.

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-787

The program writes past the bounds of a buffer, overwriting adjacent memory an attacker can turn to their advantage. Crafted input can overwrite control data and redirect execution. Remediation is validating every index and length before a write, plus modern memory-safety mitigations.

General guidance for the out-of-bounds write 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
D6220 FirmwareOperating system
Affected:< 1.0.0.68
D6400 FirmwareOperating system
Affected:< 1.0.0.102
D7000v2 FirmwareOperating system
Affected:< 1.0.0.74
D8500 FirmwareOperating system
Affected:< 1.0.3.60
Dc112a FirmwareOperating system
Affected:< 1.0.0.56
R6300v2 FirmwareOperating system
Affected:< 1.0.4.50
R6400 FirmwareOperating system
Affected:< 1.0.1.68
R7000 FirmwareOperating system
Affected:< 1.0.11.116

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 1.0.0.56 / 1.0.0.68 / 1.0.0.74 or later
Fixed in 1.0.0.561.0.0.681.0.0.74
Vendor patch kb.netgear.com →
Recommended fix High confidence

NETGEAR firmware 1.0.0.68 (D6220), 1.0.0.102 (D6400), 1.0.0.74 (D7000v2), 1.0.3.60 (D8505), 1.0.0.56 (DC112A), 1.0.4.50 (R6300v2), 1.0.1.68 (R6400), or 1.0.11.116 (R7000) - or later stable releases

  1. 1. Identify your NETGEAR router model from the affected list (D6220, D6400, D7000v2, D8500, DC112A, R6300v2, R6400, or R7000)
  2. 2. Access the router's web management interface and navigate to the Administration or Settings section
  3. 3. Locate the Firmware Update or Router Upgrade option
  4. 4. Check the current firmware version under Router Info or Advanced > Administration > Router Status
  5. 5. Download the appropriate fixed firmware version from NETGEAR's official support site: https://www.netgear.com/support/
  6. 6. In the router's firmware update page, select the downloaded firmware file and click Upload or Apply
  7. 7. Wait for the firmware upload and installation to complete - do not power off the router
  8. 8. After reboot, verify the new firmware version matches or exceeds the fixed version for your model (D6220: 1.0.0.68, D6400: 1.0.0.102, D7000v2: 1.0.0.74, D8500: 1.0.3.60, DC112A: 1.0.0.56, R6300v2: 1.0.4.50, R6400: 1.0.1.68, R7000: 1.0.11.116)
Caveat Firmware updates may reset router configuration to defaults; backup configuration before upgrade and reapply after

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

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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-2021-45638 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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