Vulnerability · Published Mar 5, 2021 · Assigned by zdi

CVE-2021-27256

High 8.8

In plain English

A high-severity OS command injection in R7800 from NETGEAR. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 62% of all known vulnerabilities).

Severity (CVSS 3.0)8.8High

Exploit odds (30 days)1.0%top 38.2% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
NETGEAR	R7800	firmware version 1.0.2.76

Weakness: CWE-78 · Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders x_refsource_MISC
https://www.zerodayinitiative.com/advisories/ZDI-21-262/ x_refsource_MISC