CVE-2021-33719 Memory corruption in SIPROTEC 5 relays with CPU variants CP050

Q: Is CVE-2021-33719 being exploited?

There is no known exploitation of CVE-2021-33719 in the wild and no public exploit code.

Q: How do I fix CVE-2021-33719?

No fix has been published for CVE-2021-33719 yet. Limit exposure of the affected software until one is available.

Critical 9.8 Published 14 Sep 2021 Updated 3 Aug 2024

Attackers can cause denial of service or remote code execution on SIPROTEC 5 relays by sending crafted packets to port 4443.

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-2021-33719?

CVE-2021-33719 is a critical memory corruption vulnerability in Siemens SIPROTEC 5 relays with CPU variants CP050, published on 14 Sep 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 SIPROTEC 5 relays with CPU variants CP050 (All versions < V8.80), SIPROTEC 5 relays with CPU variants CP100 (All versions < V8.80), SIPROTEC 5 relays with CPU variants CP300 (All versions < V8.80). Specially crafted packets sent to port 4443/tcp could cause a Denial-of-Service condition or potential remote code execution.

Weakness: CWE-120

Which versions are affected by CVE-2021-33719?

It affects 3 products.

Products include Siemens Siprotec 5 With Cpu Variant Cp050, Siemens Siprotec 5 With Cpu Variant Cp100, Siemens Siprotec 5 With Cpu Variant Cp300.

How do I fix CVE-2021-33719?

No fix has been published for CVE-2021-33719 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-33719 being exploited?

There is no known exploitation of CVE-2021-33719 in the wild and no public exploit code.

Sources

Also known as GHSA-6936-h7xw-gfq3.