CVE-2021-27239

highpriority · track · 35EPSS 0.008 · 55 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.77% (55th) EPSS

CVSS 8.3 · high

Is it mine?

37 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-27

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R6400 and R6700 firmware version 1.0.4.98 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the upnpd service, which listens on UDP port 1900 by default. A crafted MX header field in an SSDP message can trigger an overflow of a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-11851.

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

v3.18.1highCVSS: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-121US

affected products (37)

Products and version ranges known to be affected.

Netgear Multiple Routers≤ firmware version 1.0.4.98enisa_euvdEU
netgear d6220 firmware< 1.0.0.68nvdUScpe:2.3:o:netgear:d6220_firmware:*:*:*:*:*:*:*:*
netgear d6400 firmware< 1.0.0.102nvdUScpe:2.3:o:netgear:d6400_firmware:*:*:*:*:*:*:*:*
netgear d7000 firmware< 1.0.0.66nvdUScpe:2.3:o:netgear:d7000_firmware:*:*:*:*:*:*:*:*
netgear d8500 firmware< 1.0.3.60nvdUScpe:2.3:o:netgear:d8500_firmware:*:*:*:*:*:*:*:*
netgear dc112a firmware< 1.0.0.54nvdUScpe:2.3:o:netgear:dc112a_firmware:*:*:*:*:*:*:*:*
netgear ex7000 firmware< 1.0.1.94nvdUScpe:2.3:o:netgear:ex7000_firmware:*:*:*:*:*:*:*:*
netgear ex7500 firmware< 1.0.0.72nvdUScpe:2.3:o:netgear:ex7500_firmware:*:*:*:*:*:*:*:*
netgear r6250 firmware< 1.0.4.48nvdUScpe:2.3:o:netgear:r6250_firmware:*:*:*:*:*:*:*:*
netgear r6300 firmware< 1.0.4.50nvdUScpe:2.3:o:netgear:r6300_firmware:*:*:*:*:*:*:*:*
netgear r6400 firmware< 1.0.1.68nvdUScpe:2.3:o:netgear:r6400_firmware:*:*:*:*:*:*:*:*
netgear r6400 firmware< 1.0.4.102nvdUScpe:2.3:o:netgear:r6400_firmware:*:*:*:*:*:*:*:*
netgear r6700 firmware< 1.0.4.102nvdUScpe:2.3:o:netgear:r6700_firmware:*:*:*:*:*:*:*:*
netgear r6900p firmware< 1.3.2.132nvdUScpe:2.3:o:netgear:r6900p_firmware:*:*:*:*:*:*:*:*
netgear r7000 firmware< 1.0.11.116nvdUScpe:2.3:o:netgear:r7000_firmware:*:*:*:*:*:*:*:*
netgear r7000p firmware< 1.3.2.132nvdUScpe:2.3:o:netgear:r7000p_firmware:*:*:*:*:*:*:*:*
netgear r7100lg firmware< 1.0.0.64nvdUScpe:2.3:o:netgear:r7100lg_firmware:*:*:*:*:*:*:*:*
netgear r7850 firmware< 1.0.5.68nvdUScpe:2.3:o:netgear:r7850_firmware:*:*:*:*:*:*:*:*
netgear r7900 firmware< 1.0.4.38nvdUScpe:2.3:o:netgear:r7900_firmware:*:*:*:*:*:*:*:*
netgear r7900p firmware< 1.4.1.68nvdUScpe:2.3:o:netgear:r7900p_firmware:*:*:*:*:*:*:*:*

showing 20 of 37

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-03-29modified 2026-06-17

references (7)

External citations — patches, advisories, analysis.

scry

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