CVE-2021-34991
This vulnerability allows network-adjacent attackers to execute arbitrary code on affected...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2021-34991- CVSS 3.0
- 8.8 High
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-121
- Updated
- 2026-11-02
EUVDEUVD-2021-21638
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.
- Record
EUVD-2021-21638- CVSS 3.0
- 8.8 High
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-4fwh-3qpr-42ff No score
This vulnerability allows network-adjacent attackers to execute arbitrary code on affected...
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.
- Record
GHSA-4fwh-3qpr-42ff- Weakness
- CWE-787
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2021-34991- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.0
- 8.8 High
CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 8.3 High
AV:A/AC:L/Au:N/C:C/I:C/A:C - Weakness
- CWE-121, CWE-787
- Updated
- 2026-11-02
Affected products
- netgear r6400v2
- netgear cax80 firmware
- netgear d6220 firmware
- netgear d6400 firmware
- netgear d7000v2 firmware
- netgear dc112a firmware
- netgear dgn2200v4 firmware
- netgear ex3700 firmware
- netgear ex3800 firmware
- netgear ex6120 firmware
- netgear ex6130 firmware
- netgear r6400 firmware
Show 33 moreShow less
- netgear r6400v2 firmware
- netgear r6700v3 firmware
- netgear r6900p firmware
- netgear r7000 firmware
- netgear r7000p firmware
- netgear r7100lg firmware
- netgear r7850 firmware
- netgear r7900p firmware
- netgear r7960p firmware
- netgear r8000 firmware
- netgear r8000p firmware
- netgear r8300 firmware
- netgear r8500 firmware
- netgear rax15 firmware
- netgear rax200 firmware
- netgear rax20 firmware
- netgear rax35v2 firmware
- netgear rax38v2 firmware
- netgear rax40v2 firmware
- netgear rax42 firmware
- netgear rax43 firmware
- netgear rax45 firmware
- netgear rax48 firmware
- netgear rax50 firmware
- netgear rax50s firmware
- netgear rax75 firmware
- netgear rax80 firmware
- netgear raxe450 firmware
- netgear raxe500 firmware
- netgear rs400 firmware
- netgear wndr3400v3 firmware
- netgear wnr3500lv2 firmware
- netgear xr300 firmware
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-34991 is a high vulnerability (CVSS 8.8) in Netgear R6400v2, published November 15, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 5.71%, the 93rd percentile. No source names a fixed version.