SIMATIC CP 1242-7 V2: Out-of-bounds Write
CVE-2022-34819 is a critical-severity out-of-bounds write vulnerability in SIMATIC CP 1242-7 V2 from Siemens, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected SIMATIC CP 1242-7 V2 versions: All versions < V3.3.46. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.13% chance of exploitation within 30 days, higher than 82% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Simatic Cp 1543-1 Firmware to 3.0.22 or a later version.
- Update Siplus Net Cp 1543-1 Firmware to 3.0.22 or a later version.
- Read the advisory on cert-portal.siemens.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE; 5 further products are omitted here. 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
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:N/UI:N/S:C/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 | 10.0 | Critical | NVD |
| CVSS 2.0 | 9.3 | High | NVD |
Official description
A vulnerability has been identified in SIMATIC CP 1242-7 V2 (All versions < V3.3.46), SIMATIC CP 1243-1 (All versions < V3.3.46), SIMATIC CP 1243-7 LTE EU (All versions < V3.3.46), SIMATIC CP 1243-7 LTE US (All versions < V3.3.46), SIMATIC CP 1243-8 IRC (All versions < V3.3.46), SIMATIC CP 1542SP-1 IRC (All versions >= V2.0 < V2.2.28), SIMATIC CP 1543-1 (All versions < V3.0.22), SIMATIC CP 1543SP-1 (All versions >= V2.0 < V2.2.28), SIPLUS ET 200SP CP 1542SP-1 IRC TX RAIL (All versions >= V2.0 < V2.2.28), SIPLUS ET 200SP CP 1543SP-1 ISEC (All versions >= V2.0 < V2.2.28), SIPLUS ET 200SP CP 1543SP-1 ISEC TX RAIL (All versions >= V2.0 < V2.2.28), SIPLUS NET CP 1242-7 V2 (All versions < V3.3.46), SIPLUS NET CP 1543-1 (All versions < V3.0.22), SIPLUS S7-1200 CP 1243-1 (All versions < V3.3.46), SIPLUS S7-1200 CP 1243-1 RAIL (All versions < V3.3.46). The application lacks proper validation of user-supplied data when parsing specific messages. This could result in a heap-based buffer overflow. An attacker could leverage this vulnerability to execute code in the context of device.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in SIMATIC CP 1242-7 V2
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Out-of-bounds Write vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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