CVE-2018-16523: FreeRTOS TCP/IP

[senier]

Description

The TCP_OPT_MSS handler also contains a DoS vulnerability.

Root cause

Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS Connect middleware TCP/IP component allow division by zero in prvCheckOptions.

When recalculating the RxWindowLength, if an attacker supplies an MSS of 0, this line will divide by 0 thus raising an exception and causing a DoS.

Software

Name

FreeRTOS

Versions affected

1.3.1 - 10.0.1

Links

• CVE Entry
• In-depth analysis