SIMATIC PCS 7: Improper Control of Generation of Code
CVE-2023-25910 is a high-severity improper control of generation of code vulnerability in SIMATIC PCS 7 from Siemens, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version V9.1 SP2 UC04 as the first without the flaw, so updating SIMATIC PCS 7 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1% chance of exploitation within 30 days, higher than 63% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update SIMATIC PCS 7 to V9.1 SP2 UC04 or a later version.
- Update SIMATIC S7-PM to V5.7 SP1 HF1 or V5.7 SP2 HF1, whichever matches your release line, or a later version.
- Update SIMATIC STEP 7 V5 to V5.7 or a later version.
- Read the advisory on cert-portal.siemens.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Siemens | SIMATIC PCS 7 | before V9.1 SP2 UC04 | V9.1 SP2 UC04 |
| Siemens | SIMATIC S7-PM | before V5.7 SP1 HF1; before V5.7 SP2 HF1 | V5.7 SP1 HF1, V5.7 SP2 HF1 |
| Siemens | SIMATIC STEP 7 V5 | before V5.7 | V5.7 |
| Siemens | Simatic Step 7 | before 5.7 | 5.7 |
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
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- 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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 10.0 | Critical | CNA (siemens.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
A vulnerability has been identified in SIMATIC PCS 7 (All versions < V9.1 SP2 UC04), SIMATIC S7-PM (All versions < V5.7 SP1 HF1), SIMATIC S7-PM (All versions < V5.7 SP2 HF1), SIMATIC STEP 7 V5 (All versions < V5.7). The affected product contains a database management system that could allow remote users with low privileges to use embedded functions of the database (local or in a network share) that have impact on the server. An attacker with network access to the server network could leverage these embedded functions to run code with elevated privileges in the database management system's server.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How developers prevent this class of flaw
- Refactor your program so that you do not have to dynamically generate code.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
More Improper Control of Generation of Code vulnerabilities (CWE-94)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
Other vulnerabilities in SIMATIC PCS 7
- 8.8 High severity
- 7.8 High severity
Recent Improper Control of Generation of Code vulnerabilities
- 7.2 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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