SB2024031331 - Remote code execution in FortiOS and FortiProxy captive portal

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Out-of-bounds write (CVE-ID: CVE-2023-42789)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input in captive portal. A remote attacker can send specially crafted HTTP requests to the affected device, trigger an out-of-bounds write and execute arbitrary code on the target system.

2) Stack-based buffer overflow (CVE-ID: CVE-2023-42790)

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

The vulnerability exists due to a boundary error when processing specially crafted HTTP requests in captive portal. A remote unauthenticated attacker can trigger a stack-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Remediation

Install update from vendor's website.

References

• https://fortiguard.com/psirt/FG-IR-23-328
• https://fortiguard.com/psirt/FG-IR-23-327