Vulnerability · Published Nov 15, 2021 · Assigned by zdi

CVE-2021-34991

High 8.8

In plain English

A high-severity stack buffer overflow in R6400v2 from NETGEAR. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 5.7% (higher than 93% of all known vulnerabilities).

Severity (CVSS 3.0)8.8High

Exploit odds (30 days)5.7%top 6.9% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
NETGEAR	R6400v2	1.0.4.106_10.0.80

Weakness: CWE-121 · Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://www.zerodayinitiative.com/advisories/ZDI-21-1303/ x_refsource_MISC
https://kb.netgear.com/000064361/Security-Advisory-for-Pre-Authentication-Buffer-Overflow-on-Multiple-Products-PSV-2021-0168 x_refsource_MISC