RCE in NETGEAR Br200

CVE-2021-27256

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R7800 firmware version 1.0.2.76. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the handling of the rc_service parameter provided to apply_save.cgi. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12355.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.010 (60.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 60.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-27256: held from 0.009 to 0.010.

EPSS over last 30 days · oldest: 0.009 · newest: 0.010 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-27256?
CVE-2021-27256 is a high-severity vulnerability in NETGEAR Br200, classified under OS Command Injection. CVSS score: 8.8/10. Published 2021-03-05.
How severe is CVE-2021-27256?
High severity. CVSS v3 base score is 8.8 out of 10.