CVE-2021-31340 Denial of service in SIMATIC RF166C

Q: Is CVE-2021-31340 being exploited?

There is no known exploitation of CVE-2021-31340 in the wild and no public exploit code.

Q: How do I fix CVE-2021-31340?

No fix has been published for CVE-2021-31340 yet. Limit exposure of the affected software until one is available.

High 7.5 Published 8 Jun 2021 Updated 3 Aug 2024

An attacker can cause a Denial-of-Service condition on Siemens SIMATIC RFID readers by sending a large number of incoming connections.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-31340?

CVE-2021-31340 is a high-severity denial of service vulnerability in Siemens SIMATIC RF166C, published on 8 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability has been identified in SIMATIC RF166C (All versions > V1.1 and < V1.3.2), SIMATIC RF185C (All versions > V1.1 and < V1.3.2), SIMATIC RF186C (All versions > V1.1 and < V1.3.2), SIMATIC RF186CI (All versions > V1.1 and < V1.3.2), SIMATIC RF188C (All versions > V1.1 and < V1.3.2), SIMATIC RF188CI (All versions > V1.1 and < V1.3.2), SIMATIC RF360R (All versions < V2.0), SIMATIC Reader RF610R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF610R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF610R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF615R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF615R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF615R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF650R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF650R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF650R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF680R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF680R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF680R FCC (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ARIB (All versions > V3.0 < V4.0), SIMATIC Reader RF685R CMIIT (All versions > V3.0 < V4.0), SIMATIC Reader RF685R ETSI (All versions > V3.0 < V4.0), SIMATIC Reader RF685R FCC (All versions > V3.0 < V4.0). Affected devices do not properly handle large numbers of incoming connections. An attacker may leverage this to cause a Denial-of-Service situation.

Weakness: CWE-400

Which versions are affected by CVE-2021-31340?

It affects 25 products.

Products include Siemens Simatic Reader Rf610r Cmiit Firmware, Siemens Simatic Reader Rf610r Etsi Firmware, Siemens Simatic Reader Rf610r Fcc Firmware, Siemens Simatic Reader Rf615r Cmiit Firmware, Siemens Simatic Reader Rf615r Etsi Firmware, Siemens Simatic Reader Rf615r Fcc Firmware and 19 more.

How do I fix CVE-2021-31340?

No fix has been published for CVE-2021-31340 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-2021-31340 being exploited?

There is no known exploitation of CVE-2021-31340 in the wild and no public exploit code.

Sources

Also known as GHSA-hjxf-6qxm-x8qg.