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)
EPSS: 0.009 (55.1th percentile) — read the EPSS interpretation.
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.
Affected products
Weakness classification (CWE)
References
- zdi-disclosures@trendmicro.com (Patch, x_refsource_MISC, Vendor Advisory)
- zdi-disclosures@trendmicro.com (VDB Entry, Third Party Advisory, x_refsource_MISC)
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.