CVE-2020-27861: NETGEAR CBK40 Firmware

High severity, CVSS 8.8. EPSS: 2% chance of exploitation in the next 30 days.

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR Orbi 2.5.1.16 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the UA_Parser utility. A crafted Host Name option in a DHCP request can trigger execution of a system call composed from a user-supplied string. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-11076.

Affected products

NETGEAR CBK40 Firmware: before 2.6.1.38 (fixed in 2.6.1.38)
NETGEAR CBK43 Firmware: before 2.6.1.38 (fixed in 2.6.1.38)
NETGEAR CBR40 Firmware: before 2.6.1.38 (fixed in 2.6.1.38)
NETGEAR EX6200 Firmware: before 1.0.1.82 (fixed in 1.0.1.82)
NETGEAR EX7700 Firmware: before 1.0.0.210 (fixed in 1.0.0.210)
NETGEAR EX8000 Firmware: before 1.0.1.224 (fixed in 1.0.1.224)
NETGEAR RBK12 Firmware: before 2.6.1.44 (fixed in 2.6.1.44)
NETGEAR RBK13 Firmware: before 2.6.1.44 (fixed in 2.6.1.44)
NETGEAR RBK14 Firmware: before 2.6.1.44 (fixed in 2.6.1.44)
NETGEAR RBK15 Firmware: before 2.6.1.44 (fixed in 2.6.1.44)
NETGEAR RBK20 Router Firmware: before 2.6.1.36 (fixed in 2.6.1.36)
NETGEAR RBK20 Satellite Firmware: before 2.6.1.38 (fixed in 2.6.1.38)
NETGEAR RBK20W Firmware: before 2.6.1.36 (fixed in 2.6.1.36)
NETGEAR RBK22 Router Firmware: before 2.6.1.36 (fixed in 2.6.1.36)
NETGEAR RBK22 Satellite Firmware: before 2.6.1.38 (fixed in 2.6.1.38)
NETGEAR RBK23 Router Firmware: before 2.6.1.36 (fixed in 2.6.1.36)
NETGEAR RBK23 Satellite Firmware: before 2.6.1.38 (fixed in 2.6.1.38)
NETGEAR RBK23W Firmware: before 2.6.1.36 (fixed in 2.6.1.36)
NETGEAR RBK30 Firmware: before 2.6.1.36 (fixed in 2.6.1.36)
NETGEAR RBK33 Firmware: before 2.6.1.36 (fixed in 2.6.1.36)
NETGEAR RBK40 Router Firmware: before 2.6.1.36 (fixed in 2.6.1.36)
NETGEAR RBK40 Satellite Firmware: before 2.6.1.38 (fixed in 2.6.1.38)
NETGEAR RBK43 Router Firmware: before 2.6.1.36 (fixed in 2.6.1.36)
NETGEAR RBK43 Satellite Firmware: before 2.6.1.38 (fixed in 2.6.1.38)
NETGEAR RBK43S Router Firmware: before 2.6.1.36 (fixed in 2.6.1.36)
and 14 more

Published 2021-02-12. Last modified 2026-06-17.