CVE-2021-34991

highpriority · track · 37EPSS 0.057 · 93 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

5.67% (93rd) EPSS

CVSS 8.3 · high

Is it mine?

89 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · fstec_bdu

EPSS · scored 2026-10-27

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R6400v2 1.0.4.106_10.0.80 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the UPnP service, which listens on TCP port 5000 by default. When parsing the uuid request header, the process does not properly validate the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-14110.

cvss

Technical severity, 0–10. One row per scoring source.

8.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.08.3highAV:A/AC:L/Au:N/C:C/I:C/A:Cprimary · NVD / NIST USexploitability 6.5 · impact 10

v3.18.8highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 5.9

v3.08.8highCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.08.8highCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · zdi-disclosures@trendmicro.comexploitability 2.8 · impact 5.9

v3.18.8highAV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.18.1highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-787USprimaryCWE-121USCWE-121USCWE-787US

affected products (89)

Products and version ranges known to be affected.

NETGEAR R6400v2≤ 1.0.4.106_10.0.80enisa_euvdEU
NETGEAR AirCards DC112A≤ 1.0.0.62fstec_bduRU
NETGEAR CAX80≤ 2.1.3.5fstec_bduRU
NETGEAR D6220≤ 1.0.0.76fstec_bduRU
NETGEAR D6400≤ 1.0.0.108fstec_bduRU
NETGEAR D7000v2≤ 1.0.0.76fstec_bduRU
NETGEAR DGN2200v4≤ 1.0.0.126fstec_bduRU
NETGEAR EX3700≤ 1.0.0.94fstec_bduRU
NETGEAR EX3800≤ 1.0.0.94fstec_bduRU
NETGEAR EX6120≤ 1.0.0.66fstec_bduRU
NETGEAR EX6130≤ 1.0.0.66fstec_bduRU
NETGEAR R6400≤ 1.0.1.76fstec_bduRU
NETGEAR R6400v2≤ 1.0.4.120fstec_bduRU
NETGEAR R6700v3≤ 1.0.4.120fstec_bduRU
NETGEAR R6900P≤ 1.3.3.142_HOTFIXfstec_bduRU
NETGEAR R7000≤ 1.0.11.128fstec_bduRU
NETGEAR R7000P≤ 1.3.3.142_HOTFIXfstec_bduRU
NETGEAR R7100LG≤ 1.0.0.72fstec_bduRU
NETGEAR R7850≤ 1.0.5.76fstec_bduRU
NETGEAR R7900≤ 1.4.2.84fstec_bduRU

showing 20 of 89

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu NVD CVE.org MITRE

published 2021-11-15modified 2026-06-17

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+16120 more

references (7)

External citations — patches, advisories, analysis.

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