Advisory Details

October 29th, 2021

NETGEAR Multiple Routers httpd Stack-based Buffer Overflow Remote Code Execution Vulnerability

ZDI-21-1274
ZDI-CAN-13709

CVE ID CVE-2021-34982
CVSS SCORE 8.8, AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
AFFECTED VENDORS NETGEAR
AFFECTED PRODUCTS Multiple Routers
VULNERABILITY DETAILS

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of multiple NETGEAR routers. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the httpd service, which listens on TCP port 80 by default. When parsing the strings file, 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.

ADDITIONAL DETAILS NETGEAR has issued an update to correct this vulnerability. More details can be found at:
https://kb.netgear.com/000064313/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Some-Extenders-Routers-and-DSL-Modem-Routers-PSV-2021-0159
DISCLOSURE TIMELINE
  • 2021-06-30 - Vulnerability reported to vendor
  • 2021-10-29 - Coordinated public release of advisory
CREDIT Sungur Labs
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