CVE-2018-21153 [Critical] | Memory Corruption in D7800 Firmware

Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects D7800 before 1.0.1.34, DM200 before 1.0.0.50, EX2700 before 1.0.1.32, EX6100v2 before 1.0.1.70, EX6150v2 before 1.0.1.70, EX6200v2 before 1.0.1.62, EX6400 before 1.0.1.78, EX7300 before 1.0.1.62, EX8000 before 1.0.0.114, R6100 before 1.0.1.22, R7500 before 1.0.0.122, R7500v2 before 1.0.3.26, R7800 before 1.0.2.40, R8900 before 1.0.3.10, R9000 before 1.0.3.10, WN2000RPTv3 before 1.0.1.26, WN3000RPv2 before 1.0.0.56, WN3000RPv3 before 1.0.2.66, WN3100RPv2 before 1.0.0.56, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.54, WNDR4500v3 before 1.0.0.54, and WNR2000v5 before 1.0.0.64.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.56%	1.54%	+0.99%
2	2025-03-30	1.08%	0.56%	-0.52%
3	2025-03-29	—	1.08%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.56%

1.54%

+0.99%

2025-03-30

1.08%

0.56%

-0.52%

2025-03-29

—

1.08%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
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]
8.8	3.0	HIGH	`CVSS:3.0/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]
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

9.8

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]

8.8

3.0

HIGH

CVSS:3.0/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]

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-2018-21153

Vendor	Product	Version	Raw CPE
netgear	d7800_firmware	< 1.0.1.34	cpe:2.3:o:netgear:d7800_firmware::::::::
netgear	dm200_firmware	< 1.0.0.50	cpe:2.3:o:netgear:dm200_firmware::::::::
netgear	ex2700_firmware	< 1.0.1.32	cpe:2.3:o:netgear:ex2700_firmware::::::::
netgear	ex6100_firmware	< 1.0.1.70	cpe:2.3:o:netgear:ex6100_firmware::::::::
netgear	ex6150_firmware	< 1.0.1.70	cpe:2.3:o:netgear:ex6150_firmware::::::::
netgear	ex6200_firmware	< 1.0.1.62	cpe:2.3:o:netgear:ex6200_firmware::::::::
netgear	ex6400_firmware	< 1.0.1.78	cpe:2.3:o:netgear:ex6400_firmware::::::::
netgear	ex7300_firmware	< 1.0.1.62	cpe:2.3:o:netgear:ex7300_firmware::::::::
netgear	ex8000_firmware	< 1.0.0.114	cpe:2.3:o:netgear:ex8000_firmware::::::::
netgear	r6100_firmware	< 1.0.1.22	cpe:2.3:o:netgear:r6100_firmware::::::::
netgear	r7500_firmware	< 1.0.0.122	cpe:2.3:o:netgear:r7500_firmware::::::::
netgear	r7500_firmware	< 1.0.3.26	cpe:2.3:o:netgear:r7500_firmware::::::::
netgear	r7800_firmware	< 1.0.2.40	cpe:2.3:o:netgear:r7800_firmware::::::::
netgear	r8900_firmware	< 1.0.3.10	cpe:2.3:o:netgear:r8900_firmware::::::::
netgear	r9000_firmware	< 1.0.3.10	cpe:2.3:o:netgear:r9000_firmware::::::::
netgear	wn2000rpt_firmware	< 1.0.1.26	cpe:2.3:o:netgear:wn2000rpt_firmware::::::::
netgear	wn3000rp_firmware	< 1.0.0.56	cpe:2.3:o:netgear:wn3000rp_firmware::::::::
netgear	wn3000rp_firmware	< 1.0.2.66	cpe:2.3:o:netgear:wn3000rp_firmware::::::::
netgear	wn3100rp_firmware	< 1.0.0.56	cpe:2.3:o:netgear:wn3100rp_firmware::::::::
netgear	wndr4300_firmware	< 1.0.2.98	cpe:2.3:o:netgear:wndr4300_firmware::::::::
netgear	wndr4300_firmware	< 1.0.0.54	cpe:2.3:o:netgear:wndr4300_firmware::::::::
netgear	wndr4500_firmware	< 1.0.0.54	cpe:2.3:o:netgear:wndr4500_firmware::::::::
netgear	wnr2000_firmware	< 1.0.0.64	cpe:2.3:o:netgear:wnr2000_firmware::::::::

References for CVE-2018-21153

URL	Tags
https://kb.netgear.com/000059480/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Some-Gateways-Routers-and-Extenders-PSV-2017-3136	Vendor Advisory

URL

CVE-2018-21153

Exploit prediction scoring system (EPSS) score for CVE-2018-21153

Common vulnerability scoring system (CVSS) metrics for CVE-2018-21153

Weakness enumeration for CVE-2018-21153

Affected software / configurations for CVE-2018-21153

References for CVE-2018-21153