SIMATIC PCS neo V4.0: Deserialization of Untrusted Data
CVE-2022-45147 is a high-severity deserialization of untrusted data vulnerability in SIMATIC PCS neo V4.0 from Siemens, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected SIMATIC PCS neo V4.0 versions: all versions. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.23% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update SIMATIC STEP 7 V18 to V18 Update 2 or a later version.
- Update simatic_pcs_neo to 5.0 or a later version.
- Update simatic_step_7 to 17 or 18 or 18_update_2, whichever matches your release line, or a later version.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Siemens | SIMATIC PCS neo V4.0 | all versions | Not stated |
| Siemens | SIMATIC STEP 7 V16 | all versions | Not stated |
| Siemens | SIMATIC STEP 7 V17 | all versions | Not stated |
| Siemens | SIMATIC STEP 7 V18 | before V18 Update 2 | V18 Update 2 |
| Siemens | simatic_pcs_neo | 4.0 up to, but not including, 5.0 | 5.0 |
| Siemens | simatic_step_7 | 16 up to, but not including, 17; 17 up to, but not including, 18; 18 up to, but not including, 18_update_2 | 17, 18, 18_update_2 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA (siemens.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.5 | High | CNA (siemens.com) |
| CVSS 3.1 | 7.8 | High | CNA (siemens.com) |
Official description
A vulnerability has been identified in SIMATIC PCS neo V4.0 (All versions), SIMATIC STEP 7 V16 (All versions), SIMATIC STEP 7 V17 (All versions), SIMATIC STEP 7 V18 (All versions < V18 Update 2). Affected applications do not properly restrict the .NET BinaryFormatter when deserializing user-controllable input. This could allow an attacker to cause a type confusion and execute arbitrary code within the affected application. This is the same issue that exists for .NET BinaryFormatter https://docs.microsoft.com/en-us/visualstudio/code-quality/ca2300.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in SIMATIC PCS neo V4.0
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
Recent Deserialization of Untrusted Data vulnerabilities
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Microsoft SharePoint Deserialization Exploited
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