CVE-2020-8867 Insufficient Session Expiration and TOCTOU Race Condition in OPC FOundation UA .Net Standard
Remote attackers can cause a denial-of-service condition in OPC Foundation UA .NET Standard by exploiting a race condition in session handling without authentication.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-8867?
CVE-2020-8867 is a medium-severity vulnerability in OPC Foundation UA .NET Standard, published on 22 Apr 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of OPC Foundation UA .NET Standard 1.04.358.30. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of sessions. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to create a denial-of-service condition against the application. Was ZDI-CAN-10295.
Which versions are affected by CVE-2020-8867?
2 open source packages ship an affected version, including OPCFoundation.NetStandard.Opc.Ua. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
OPCFoundation.NetStandard.Opc.Ua NuGet | All versions | 1.4.359.31 |
OPCFoundation.NetStandard.Opc.Ua NuGet | All versions | 1.4.359.31 |
Products include Opcfoundation Unified Architecture .Net-Standard.
How do I fix CVE-2020-8867?
Upgrade OPCFoundation.NetStandard.Opc.Ua to 1.4.359.31 or later.
Is CVE-2020-8867 being exploited?
There is no known exploitation of CVE-2020-8867 in the wild and no public exploit code.
Sources
Also known as GHSA-9q94-v7ch-mxqw.