CVE-2021-40847: netgear r6400v2_firmware

Vulnerability summary

CVE-2021-40847 is a high (CVSS 9.3) vulnerability in netgear r6400v2_firmware. EPSS estimates a 10.01% chance of exploitation in the next 30 days, higher than 95.5% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 21-09-2021
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

The update process of the Circle Parental Control Service on various NETGEAR routers allows remote attackers to achieve remote code execution as root via a MitM attack. While the parental controls themselves are not enabled by default on the routers, the Circle update daemon, circled, is enabled by default. This daemon connects to Circle and NETGEAR to obtain version information and updates to the circled daemon and its filtering database. However, database updates from NETGEAR are unsigned and downloaded via cleartext HTTP. As such, an attacker with the ability to perform a MitM attack on the device can respond to circled update requests with a crafted, compressed database file, the extraction of which gives the attacker the ability to overwrite executable files with attacker-controlled code. This affects R6400v2 1.0.4.106, R6700 1.0.2.16, R6700v3 1.0.4.106, R6900 1.0.2.16, R6900P 1.3.2.134, R7000 1.0.11.123, R7000P 1.3.2.134, R7850 1.0.5.68, R7900 1.0.4.38, R8000 1.0.4.68, and RS400 1.5.0.68.

• CWE-319Cleartext Transmission of Sensitive InformationThe product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.