Is CVE-2021-34947 actively exploited?

No active exploitation of CVE-2021-34947 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-34947 be exploited remotely?

Partially. CVE-2021-34947 requires adjacent network access (same network segment) to exploit.

What is the CVSS score of CVE-2021-34947?

CVE-2021-34947 has a CVSS score of 8.8 (HIGH).

HOME VULNERABILITIESCVE-2021-34947

HIGH

CVE-2021-34947

CWE-787Published: May 7, 2024· Updated: Jun 17, 2026

8.8

CVSS v3.1

Official Description

NETGEAR R7800 net-cgi Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R7800 routers. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the parsing of the soap_block_table file. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated data structure. An attacker can leverage this vulnerability to execute code in the context of root.

. Was ZDI-CAN-13055.

NVD Source

Technical Analysis

CVE-2021-34947 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.