high
8.8
CWE
121
Advisory Published
Updated
Advisory Published

CVE-2021-27239: NETGEAR Multiple Routers SSDP Stack-based Buffer Overflow Remote Code Execution Vulnerability

First published: Mon Mar 29 2021(Updated: )

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.

Credit: zdi-disclosures@trendmicro.com

Affected SoftwareAffected VersionHow to fix
NETGEAR Multiple Devices
Netgear D6220 Firmware<1.0.0.68
NETGEAR D6220 firmware
NETGEAR D6400<1.0.0.102
NETGEAR D6400 firmware
NETGEAR D7000v1 firmware<1.0.0.66
NETGEAR D7000 firmware=v2
Netgear D8500 Firmware<1.0.3.60
Netgear D8500 Firmware
NETGEAR DC112A firmware<1.0.0.54
Netgear DC112A
NETGEAR EX7000 firmware<1.0.1.94
NETGEAR EX7000 firmware
NETGEAR EX7500<1.0.0.72
NETGEAR EX7500
Netgear R6250 Firmware<1.0.4.48
NETGEAR R6250
NETGEAR R6300 firmware<1.0.4.50
NETGEAR R6300 firmware=v2
NETGEAR R6400 firmware<1.0.1.68
NETGEAR R6400 firmware
NETGEAR R6400 firmware<1.0.4.102
NETGEAR R6400 firmware=v2
NETGEAR R6700 firmware<1.0.4.102
NETGEAR R6700v1 firmware=v3
NETGEAR R6900P Firmware<1.3.2.132
Netgear R6900 Firmware
NETGEAR Nighthawk R7000<1.0.11.116
NETGEAR Nighthawk R7000
NETGEAR R7000P firmware<1.3.2.132
Netgear Routers
NETGEAR R7100LG firmware<1.0.0.64
Netgear R7100LG
NETGEAR R7850 Firmware<1.0.5.68
NETGEAR R7850 firmware
NETGEAR R7900P firmware<1.0.4.38
NETGEAR R7900P firmware
NETGEAR R7900P firmware<1.4.1.68
NETGEAR R7900P firmware
NETGEAR R7960P firmware<1.4.1.68
NETGEAR R7960P firmware
NETGEAR R8000 firmware<1.0.4.68
NETGEAR R8000 firmware
NETGEAR R8000P<1.4.1.68
NETGEAR R8000P firmware
NETGEAR R8300 firmware<1.0.2.144
NETGEAR R8300 firmware
NETGEAR R8500<1.0.2.144
NETGEAR R8500
NETGEAR RAX200 firmware<1.0.2.88
NETGEAR RAX200 firmware
NETGEAR RAX75 firmware<1.0.3.102
NETGEAR RAX75 firmware
NETGEAR RAX80 firmware<1.0.3.102
NETGEAR RAX80 firmware
NETGEAR RBR750<3.2.17.12
NETGEAR RBR750 firmware
NETGEAR RBR850 firmware<3.2.17.12
NETGEAR RBR850 firmware
NETGEAR RBS40V<2.6.2.4
NETGEAR Orbi RBS40
NETGEAR RBS750<3.2.17.12
NETGEAR Orbi RBS750
NETGEAR RBS850 Firmware<3.2.17.12
NETGEAR RBS850 Firmware
NETGEAR RS400 firmware<=1.5.0.68
NETGEAR RS400 firmware
NETGEAR WNDR3400<1.0.1.38
NETGEAR WNDR3400 firmware=v3
NETGEAR WNR3500L<1.2.0.66
NETGEAR WNR3500L firmware=v2
Netgear NMS300 Firmware<1.0.3.56
Netgear NMS300 Firmware

Never miss a vulnerability like this again

Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.

Read MoreStart Free Trial

Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2021-27239?

    CVE-2021-27239 has been rated as high severity because it allows unauthenticated remote code execution on vulnerable NETGEAR routers.

  • How do I fix CVE-2021-27239?

    To address CVE-2021-27239, users should update their affected NETGEAR router firmware to the latest version provided by NETGEAR.

  • Which NETGEAR devices are affected by CVE-2021-27239?

    CVE-2021-27239 affects multiple NETGEAR router models including R6400 and R6700 with specific firmware versions.

  • Is authentication required to exploit CVE-2021-27239?

    No, authentication is not required to exploit CVE-2021-27239, making it particularly dangerous.

  • What type of attack can occur due to CVE-2021-27239?

    CVE-2021-27239 allows network-adjacent attackers to execute arbitrary code, leading potentially to a complete compromise of the affected devices.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2025 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203