edgeConnector Siemens: NULL Pointer Dereference
CVE-2023-27336 is a high-severity NULL pointer dereference vulnerability in edgeConnector Siemens from Softing, with a CVSS 3.0 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 edgeConnector Siemens versions: 3.40. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.81% chance of exploitation within 30 days, higher than 58% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Edgeaggregator to 3.70 or a later version.
- Update Secure Integration Server to 1.30 or a later version.
- 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 |
|---|---|---|---|
| Softing | edgeConnector Siemens | 3.40 | Not stated |
| Softing | edgeconnector | 3.40 | Not stated |
| Softing | Edgeaggregator | before 3.70 | 3.70 |
| Softing | Secure Integration Server | before 1.30 | 1.30 |
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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (trendmicro.com).
Official description
Softing edgeConnector Siemens OPC UA Server Null Pointer Dereference Denial-of-Service Vulnerability. This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of Softing edgeConnector Siemens. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of OPC client certificates. The issue results from dereferencing a NULL pointer. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-20508.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How developers prevent this class of flaw
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Select a programming language that is not susceptible to these issues.
- Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
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
Third-party and government advisories
- zerodayinitiative.com/advisories/ZDI-23-1065/Third Party Advisory
Other vulnerabilities in edgeConnector Siemens
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
Recent NULL Pointer Dereference vulnerabilities
- 8.8 High severity
- 7.8 High severity
- 7.5 High severity
- 7.8 High severity
- 7.6 High severity
- 7.8 High severity
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