CVE-2021-31894 Missing authorization in SIMATIC PCS 7 V8.2 and earlier
Attackers can modify device configuration metafiles due to insecure write permissions, potentially altering device behavior in Siemens industrial software.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-31894?
CVE-2021-31894 is a high-severity missing authorization vulnerability in Siemens SIMATIC PCS 7 V8.2 and earlier, published on 13 Jul 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A vulnerability has been identified in SIMATIC PCS 7 V8.2 and earlier (All versions), SIMATIC PCS 7 V9.X (All versions < V9.1 SP2), SIMATIC PDM (All versions < V9.2 SP2), SIMATIC STEP 7 V5.X (All versions < V5.7), SINAMICS STARTER (containing STEP 7 OEM version) (All versions < V5.4 SP2 HF1). A directory containing metafiles relevant to devices' configurations has write permissions. An attacker could leverage this vulnerability by changing the content of certain metafiles and subsequently manipulate parameters or behavior of devices that would be later configured by the affected software.
Weakness: CWE-732
Which versions are affected by CVE-2021-31894?
It affects 4 products.
Products include Siemens Simatic Pcs 7 Firmware, Siemens Simatic Pdm Firmware, Siemens Simatic Step 7 Firmware, Siemens Sinamics Starter Firmware.
How do I fix CVE-2021-31894?
No fix has been published for CVE-2021-31894 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2021-31894 being exploited?
There is no known exploitation of CVE-2021-31894 in the wild and no public exploit code.
Sources
Also known as GHSA-rq6h-r956-9p9r.