CVE-2021-40847
HIGHEPSS 95th pctlDescription
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.
How to fix
No published remediation has been found for this vulnerability's affected products yet.
Mitigation guidance may be in the linked vendor advisories in the References section below.
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CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Very high risk: more likely to be exploited than 95% of all known CVEs.
References
Related Vulnerabilities
Other CWE-319 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2018-12710 | High | 8.0 | 77% | - | - |
| CVE-2024-25735 | Critical | 9.1 | 51% | - | Fix |
| CVE-2019-3993 | High | 7.5 | 46% | - | - |
| CVE-2017-5259 | High | 8.8 | 39% | - | - |
| CVE-2016-5649 | Critical | 9.8 | 27% | - | - |
| CVE-2021-39341 | High | 8.2 | 22% | - | - |
Common questions
How do I fix CVE-2021-40847?
No published fix for CVE-2021-40847 has been found yet. Check the linked vendor advisories for guidance as it becomes available.
Is CVE-2021-40847 being actively exploited?
Not that we know of. CVE-2021-40847 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 10.1% is the estimated probability that it will be exploited in the next 30 days. That is higher than 95% of all scored CVEs.
How severe is CVE-2021-40847?
CVE-2021-40847 has a CVSS v3 base score of 8.1, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.