CVE-2019-5637 Beckhoff TwinCAT Profinet Driver Divide-by-Zero Denial of Service

What is CVE-2019-5637?

CVE-2019-5637 is a high-severity denial of service vulnerability in Beckhoff TwinCAT 2, published on 21 Nov 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

When Beckhoff TwinCAT is configured to use the Profinet driver, a denial of service of the controller could be reached by sending a malformed UDP packet to the device. This issue affects TwinCAT 2 version 2304 (and prior) and TwinCAT 3.1 version 4204.0 (and prior).

Weakness: CWE-369

Which versions are affected by CVE-2019-5637?

It affects 1 product.

Products include Beckhoff Twincat.

How do I fix CVE-2019-5637?

No fix has been published for CVE-2019-5637 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2019-5637 being exploited?

There is no known exploitation of CVE-2019-5637 in the wild and no public exploit code.

Other vulnerabilities in Beckhoff TwinCAT 2

• CVE-2019-16871 Auth bypass in n/a Critical 9.8
• CVE-2017-16726 Weak cryptography in Beckhoff TwinCAT Critical 9.1
• CVE-2018-7502 Privilege escalation in Beckhoff TwinCAT PLC products High 7.8
• CVE-2017-16718 Weak cryptography in Beckhoff TwinCAT Medium 5.9
• CVE-2020-12494 Beckhoff: Etherleak in TwinCAT RT network driver Medium 5.3

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-rc4x-2rwc-6x6r.