SB2020011404 - Remote code execution in Sagemcom F@st Cable Modems

Description

This security bulletin contains information about 1 security vulnerability.

1) Buffer overflow (CVE-ID: CVE-2019-19494)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when processing packets sent to spectrum analyzer build-in feature. By default the affected router accepts requests from local network only, however an attacker can craft a specially crafted webpage and use victim's browser to deliver malicious request to the affected router, e.g. via websockets and a specially crafted JSON payload.

Successful exploitation of this vulnerability may result in complete compromise of the affected router.

Note, this vulnerability was dubbed Cable Haunt by the researcher.

Remediation

Install update from vendor's website.

References

• https://cablehaunt.com
• https://github.com/Lyrebirds/Cable-Haunt-Report/releases/download/2.4/report.pdf
• https://github.com/Lyrebirds/Fast8690-exploit
• https://www.broadcom.com