OPC UA C++ Demo Server: Improper Update of Reference Count
CVE-2022-37012 is a high-severity improper update of reference count vulnerability in OPC UA C++ Demo Server from Unified Automation, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected OPC UA C++ Demo Server versions: 1.7.6-537. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.78% chance of exploitation within 30 days, higher than 79% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of OPC UA C++ Demo Server you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Unified Automation | OPC UA C++ Demo Server | 1.7.6-537 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.0 | 7.5 | High | CNA (trendmicro.com) |
Official description
This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of Unified Automation OPC UA C++ Demo Server 1.7.6-537. Authentication is not required to exploit this vulnerability. The specific flaw exists within the OpcUa_SecureListener_ProcessSessionCallRequest method. A crafted OPC UA message can force the server to incorrectly update a reference count. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-16927.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Update of Reference Count
The product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count.
More Improper Update of Reference Count vulnerabilities (CWE-911)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Third-party and government advisories
- zerodayinitiative.com/advisories/ZDI-22-1030/Third Party Advisory, VDB Entry
Other vulnerabilities in OPC UA C++ Demo Server
- 7.5 High severity
Recent Improper Update of Reference Count vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
Spotted an error? Tell us.