CVE-2021-45638 [Critical] | Out-of-bounds Write in D6220 Firmware

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.36%	1.47%	+1.11%
2	2026-04-13	0.34%	0.36%	+0.02%
3	2025-11-21	—	0.34%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.36%

1.47%

+1.11%

2026-04-13

0.34%

0.36%

+0.02%

2025-11-21

—

0.34%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
9.6	3.1	CRITICAL	`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H` Click to expand Attack vector (AV:A) Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	2.8	6.0	[email protected]
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
7.5	2.0	HIGH	`AV:N/AC:L/Au:N/C:P/I:P/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	10.0	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

9.6

3.1

CRITICAL

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H Click to expand

Attack vector (AV:A): Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

2.8

6.0

[email protected]

9.8

3.1

CRITICAL

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

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

7.5

2.0

HIGH

AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

6.4

[email protected]

Affected software / configurations for CVE-2021-45638

Vendor	Product	Version	Raw CPE
netgear	d6220_firmware	< 1.0.0.68	cpe:2.3:o:netgear:d6220_firmware::::::::
netgear	d6400_firmware	< 1.0.0.102	cpe:2.3:o:netgear:d6400_firmware::::::::
netgear	d7000v2_firmware	< 1.0.0.74	cpe:2.3:o:netgear:d7000v2_firmware::::::::
netgear	d8500_firmware	< 1.0.3.60	cpe:2.3:o:netgear:d8500_firmware::::::::
netgear	dc112a_firmware	< 1.0.0.56	cpe:2.3:o:netgear:dc112a_firmware::::::::
netgear	r6300v2_firmware	< 1.0.4.50	cpe:2.3:o:netgear:r6300v2_firmware::::::::
netgear	r6400_firmware	< 1.0.1.68	cpe:2.3:o:netgear:r6400_firmware::::::::
netgear	r7000_firmware	< 1.0.11.116	cpe:2.3:o:netgear:r7000_firmware::::::::
netgear	r7100lg_firmware	< 1.0.0.70	cpe:2.3:o:netgear:r7100lg_firmware::::::::
netgear	r7000p_firmware	< 1.3.2.132	cpe:2.3:o:netgear:r7000p_firmware::::::::
netgear	rbs40v_firmware	< 2.6.2.8	cpe:2.3:o:netgear:rbs40v_firmware::::::::
netgear	rbw30_firmware	< 2.6.2.2	cpe:2.3:o:netgear:rbw30_firmware::::::::
netgear	rs400_firmware	< 1.5.1.80	cpe:2.3:o:netgear:rs400_firmware::::::::
netgear	r6900p_firmware	< 1.3.2.132	cpe:2.3:o:netgear:r6900p_firmware::::::::

References for CVE-2021-45638

URL	Tags
https://kb.netgear.com/000064496/Security-Advisory-for-Pre-Authentication-Stack-Overflow-on-Some-Routers-PSV-2020-0464	Patch Vendor Advisory

URL

CVE-2021-45638

Exploit prediction scoring system (EPSS) score for CVE-2021-45638

Common vulnerability scoring system (CVSS) metrics for CVE-2021-45638

Weakness enumeration for CVE-2021-45638

Affected software / configurations for CVE-2021-45638

References for CVE-2021-45638