CVE-2021-45628 [Critical] | Code Injection in Cbr40 Firmware

Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects CBR40 before 2.5.0.24, CBR750 before 3.2.18.2, RBK752 before 3.2.17.12, RBR750 before 3.2.17.12, RBS750 before 3.2.17.12, RBK852 before 3.2.17.12, RBR850 before 3.2.17.12, RBS850 before 3.2.17.12, RBS40V before 2.6.2.4, and RBW30 before 2.6.2.2.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-03-30	1.78%	0.76%	-1.02%
2	2025-03-29	0.76%	1.78%	+1.02%
3	2025-03-19	—	0.76%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-03-30

1.78%

0.76%

-1.02%

2025-03-29

0.76%

1.78%

+1.02%

2025-03-19

—

0.76%

—

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]
8.8	3.1	HIGH	`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/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: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.	2.8	5.9	[email protected]
5.8	2.0	MEDIUM	`AV:A/AC:L/Au:N/C:P/I:P/A:P` Click to expand Access vector (AV:A) Requires access to an adjacent network segment. 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.	6.5	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]

8.8

3.1

HIGH

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/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: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.

2.8

5.9

[email protected]

5.8

2.0

MEDIUM

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

Access vector (AV:A): Requires access to an adjacent network segment.
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.

6.5

6.4

[email protected]

Affected software / configurations for CVE-2021-45628

Vendor	Product	Version	Raw CPE
netgear	cbr40_firmware	< 2.5.0.24	cpe:2.3:o:netgear:cbr40_firmware::::::::
netgear	cbr750_firmware	< 3.2.18.2	cpe:2.3:o:netgear:cbr750_firmware::::::::
netgear	rbk752_firmware	< 3.2.17.12	cpe:2.3:o:netgear:rbk752_firmware::::::::
netgear	rbr750_firmware	< 3.2.17.12	cpe:2.3:o:netgear:rbr750_firmware::::::::
netgear	rbs750_firmware	< 3.2.17.12	cpe:2.3:o:netgear:rbs750_firmware::::::::
netgear	rbk852_firmware	< 3.2.17.12	cpe:2.3:o:netgear:rbk852_firmware::::::::
netgear	rbr850_firmware	< 3.2.17.12	cpe:2.3:o:netgear:rbr850_firmware::::::::
netgear	rbs850_firmware	< 3.2.17.12	cpe:2.3:o:netgear:rbs850_firmware::::::::
netgear	rbs40v_firmware	< 2.6.2.4	cpe:2.3:o:netgear:rbs40v_firmware::::::::
netgear	rbs40v_firmware	2.6.2.4	cpe:2.3:o:netgear:rbs40v_firmware:2.6.2.4:::::::*
netgear	rbw30_firmware	< 2.6.2.2	cpe:2.3:o:netgear:rbw30_firmware::::::::

References for CVE-2021-45628

URL	Tags
https://kb.netgear.com/000064125/Security-Advisory-for-Pre-Authentication-Command-Injection-on-Some-WiFi-Systems-PSV-2020-0472	Patch Vendor Advisory

URL

CVE-2021-45628

Exploit prediction scoring system (EPSS) score for CVE-2021-45628

Common vulnerability scoring system (CVSS) metrics for CVE-2021-45628

Weakness enumeration for CVE-2021-45628

Affected software / configurations for CVE-2021-45628

References for CVE-2021-45628