Advisory Details

February 24th, 2021

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

ZDI-21-206
ZDI-CAN-11851

CVE ID CVE-2021-27239
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 NETGEAR R6400 and R6700 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.

ADDITIONAL DETAILS NETGEAR has issued an update to correct this vulnerability. More details can be found at:
https://kb.netgear.com/000062820/Security-Advisory-for-Stack-based-Buffer-Overflow-Remote-Code-Execution-Vulnerability-on-Some-Routers-PSV-2020-0432
DISCLOSURE TIMELINE
  • 2020-09-23 - Vulnerability reported to vendor
  • 2021-02-24 - Coordinated public release of advisory
CREDIT Anonymous
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