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CVE-2021-27239: 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...

CVE-2021-27239 · published 5 years ago

Summary

What to do

Update netgear d6220_firmware to version 1.0.0.68 or later.
Update netgear d6400_firmware to version 1.0.0.102 or later.
Update netgear d7000_firmware to version 1.0.0.66 or later.
Update netgear d8500_firmware to version 1.0.3.60 or later.
Update netgear dc112a_firmware to version 1.0.0.54 or later.
Update netgear ex7000_firmware to version 1.0.1.94 or later.
Update netgear ex7500_firmware to version 1.0.0.72 or later.
Update netgear r6250_firmware to version 1.0.4.48 or later.
Update netgear r6300_firmware to version 1.0.4.50 or later.
Update netgear r6700_firmware to version 1.0.4.102 or later.
Update netgear r6900p_firmware to version 1.3.2.132 or later.
Update netgear r7000_firmware to version 1.0.11.116 or later.
Update netgear r7000p_firmware to version 1.3.2.132 or later.
Update netgear r7100lg_firmware to version 1.0.0.64 or later.
Update netgear r7850_firmware to version 1.0.5.68 or later.
Update netgear r7900_firmware to version 1.0.4.38 or later.
Update netgear r7900p_firmware to version 1.4.1.68 or later.
Update netgear r7960p_firmware to version 1.4.1.68 or later.
Update netgear r8000_firmware to version 1.0.4.68 or later.
Update netgear r8000p_firmware to version 1.4.1.68 or later.
Update netgear r8300_firmware to version 1.0.2.144 or later.
Update netgear r8500_firmware to version 1.0.2.144 or later.
Update netgear rax200_firmware to version 1.0.2.88 or later.
Update netgear rax75_firmware to version 1.0.3.102 or later.
Update netgear rax80_firmware to version 1.0.3.102 or later.
Update netgear rbr750_firmware to version 3.2.17.12 or later.
Update netgear rbr850_firmware to version 3.2.17.12 or later.
Update netgear rbs40v_firmware to version 2.6.2.4 or later.
Update netgear rbs750_firmware to version 3.2.17.12 or later.
Update netgear rbs850_firmware to version 3.2.17.12 or later.
Update netgear wndr3400_firmware to version 1.0.1.38 or later.
Update netgear wnr3500l_firmware to version 1.2.0.66 or later.
Update netgear xr300_firmware to version 1.0.3.56 or later.

Affected software

Vendor	Product	Affected versions
netgear	d6220_firmware	< 1.0.0.68 `cpe:2.3:o:netgear:d6220_firmware::::::::`
netgear	d6400_firmware	< 1.0.0.102 `cpe:2.3:o:netgear:d6400_firmware::::::::`
netgear	d7000_firmware	< 1.0.0.66 `cpe:2.3:o:netgear:d7000_firmware::::::::`
netgear	d8500_firmware	< 1.0.3.60 `cpe:2.3:o:netgear:d8500_firmware::::::::`
netgear	dc112a_firmware	< 1.0.0.54 `cpe:2.3:o:netgear:dc112a_firmware::::::::`
netgear	ex7000_firmware	< 1.0.1.94 `cpe:2.3:o:netgear:ex7000_firmware::::::::`
netgear	ex7500_firmware	< 1.0.0.72 `cpe:2.3:o:netgear:ex7500_firmware::::::::`
netgear	r6250_firmware	< 1.0.4.48 `cpe:2.3:o:netgear:r6250_firmware::::::::`
netgear	r6300_firmware	< 1.0.4.50 `cpe:2.3:o:netgear:r6300_firmware::::::::`
netgear	r6400_firmware	< 1.0.1.68 < 1.0.4.102 `cpe:2.3:o:netgear:r6400_firmware::::::::`
netgear	r6700_firmware	< 1.0.4.102 `cpe:2.3:o:netgear:r6700_firmware::::::::`
netgear	r6900p_firmware	< 1.3.2.132 `cpe:2.3:o:netgear:r6900p_firmware::::::::`
netgear	r7000_firmware	< 1.0.11.116 `cpe:2.3:o:netgear:r7000_firmware::::::::`
netgear	r7000p_firmware	< 1.3.2.132 `cpe:2.3:o:netgear:r7000p_firmware::::::::`
netgear	r7100lg_firmware	< 1.0.0.64 `cpe:2.3:o:netgear:r7100lg_firmware::::::::`
netgear	r7850_firmware	< 1.0.5.68 `cpe:2.3:o:netgear:r7850_firmware::::::::`
netgear	r7900_firmware	< 1.0.4.38 `cpe:2.3:o:netgear:r7900_firmware::::::::`
netgear	r7900p_firmware	< 1.4.1.68 `cpe:2.3:o:netgear:r7900p_firmware::::::::`
netgear	r7960p_firmware	< 1.4.1.68 `cpe:2.3:o:netgear:r7960p_firmware::::::::`
netgear	r8000_firmware	< 1.0.4.68 `cpe:2.3:o:netgear:r8000_firmware::::::::`
netgear	r8000p_firmware	< 1.4.1.68 `cpe:2.3:o:netgear:r8000p_firmware::::::::`
netgear	r8300_firmware	< 1.0.2.144 `cpe:2.3:o:netgear:r8300_firmware::::::::`
netgear	r8500_firmware	< 1.0.2.144 `cpe:2.3:o:netgear:r8500_firmware::::::::`
netgear	rax200_firmware	< 1.0.2.88 `cpe:2.3:o:netgear:rax200_firmware::::::::`
netgear	rax75_firmware	< 1.0.3.102 `cpe:2.3:o:netgear:rax75_firmware::::::::`
netgear	rax80_firmware	< 1.0.3.102 `cpe:2.3:o:netgear:rax80_firmware::::::::`
netgear	rbr750_firmware	< 3.2.17.12 `cpe:2.3:o:netgear:rbr750_firmware::::::::`
netgear	rbr850_firmware	< 3.2.17.12 `cpe:2.3:o:netgear:rbr850_firmware::::::::`
netgear	rbs40v_firmware	< 2.6.2.4 `cpe:2.3:o:netgear:rbs40v_firmware::::::::`
netgear	rbs750_firmware	< 3.2.17.12 `cpe:2.3:o:netgear:rbs750_firmware::::::::`
netgear	rbs850_firmware	< 3.2.17.12 `cpe:2.3:o:netgear:rbs850_firmware::::::::`
netgear	rs400_firmware	<= 1.5.0.68 `cpe:2.3:o:netgear:rs400_firmware::::::::`
netgear	wndr3400_firmware	< 1.0.1.38 `cpe:2.3:o:netgear:wndr3400_firmware::::::::`
netgear	wnr3500l_firmware	< 1.2.0.66 `cpe:2.3:o:netgear:wnr3500l_firmware::::::::`
netgear	xr300_firmware	< 1.0.3.56 `cpe:2.3:o:netgear:xr300_firmware::::::::`

Original advisory text

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.

References

https://kb.netgear.com/000062820/Security-Advisory-for-Stack-based-Buffer-Overfl... Vendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-206/ Third Party Advisory VDB Entry

Fix within

Internet-facing 14 days

Internal At next upgrade

Not known to be exploited
Needs hands-on effort to exploit (estimated)
Gives an attacker full control (estimated)

Severity

8.8 High

Exploitation

<1% chance of attack within 30 days

Type

CWE-121Stack-based Buffer Overflow

Timeline

Published29 Mar 2021

Updated4 Nov 2026

First seen29 Sep 2026

Sources

CVE-2021-27239 · NVD

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