SIMATIC CP 1242-7 V2: Allocation of Resources Without Limits or Throttling
CVE-2022-43768 is a high-severity allocation of resources without limits or throttling vulnerability in SIMATIC CP 1242-7 V2 from Siemens, 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. The record lists version V3.4.29 as the first without the flaw, so updating SIMATIC CP 1242-7 V2 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.95% chance of exploitation within 30 days, higher than 62% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update SIMATIC CP 1242-7 V2 to V3.4.29 or a later version.
- Update SIMATIC CP 1243-1 to V3.4.29 or a later version.
- Update SIMATIC CP 1243-1 DNP3 (incl. SIPLUS variants) to V3.4.29 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; 21 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
- 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 CNA (siemens.com).
Official description
A vulnerability has been identified in SIMATIC CP 1242-7 V2 (6GK7242-7KX31-0XE0) (All versions < V3.4.29), SIMATIC CP 1243-1 (6GK7243-1BX30-0XE0) (All versions < V3.4.29), SIMATIC CP 1243-1 DNP3 (incl. SIPLUS variants) (All versions < V3.4.29), SIMATIC CP 1243-1 IEC (incl. SIPLUS variants) (All versions < V3.4.29), SIMATIC CP 1243-7 LTE EU (6GK7243-7KX30-0XE0) (All versions < V3.4.29), SIMATIC CP 1243-7 LTE US (6GK7243-7SX30-0XE0) (All versions < V3.4.29), SIMATIC CP 1243-8 IRC (6GK7243-8RX30-0XE0) (All versions < V3.4.29), SIMATIC CP 1542SP-1 (6GK7542-6UX00-0XE0) (All versions < V2.3), SIMATIC CP 1542SP-1 IRC (6GK7542-6VX00-0XE0) (All versions < V2.3), SIMATIC CP 1543SP-1 (6GK7543-6WX00-0XE0) (All versions < V2.3), SIMATIC CP 443-1 (6GK7443-1EX30-0XE0) (All versions < V3.3), SIMATIC CP 443-1 (6GK7443-1EX30-0XE1) (All versions < V3.3), SIMATIC CP 443-1 Advanced (6GK7443-1GX30-0XE0) (All versions < V3.3), SIPLUS ET 200SP CP 1542SP-1 IRC TX RAIL (6AG2542-6VX00-4XE0) (All versions < V2.3), SIPLUS ET 200SP CP 1543SP-1 ISEC (6AG1543-6WX00-7XE0) (All versions < V2.3), SIPLUS ET 200SP CP 1543SP-1 ISEC TX RAIL (6AG2543-6WX00-4XE0) (All versions < V2.3), SIPLUS NET CP 1242-7 V2 (6AG1242-7KX31-7XE0) (All versions < V3.4.29), SIPLUS NET CP 443-1 (6AG1443-1EX30-4XE0) (All versions < V3.3), SIPLUS NET CP 443-1 Advanced (6AG1443-1GX30-4XE0) (All versions < V3.3), SIPLUS S7-1200 CP 1243-1 (6AG1243-1BX30-2AX0) (All versions < V3.4.29), SIPLUS S7-1200 CP 1243-1 RAIL (6AG2243-1BX30-1XE0) (All versions < V3.4.29), SIPLUS TIM 1531 IRC (6AG1543-1MX00-7XE0) (All versions < V2.3.6), TIM 1531 IRC (6GK7543-1MX00-0XE0) (All versions < V2.3.6). The webserver of the affected products contains a vulnerability that may lead to a denial of service condition. An attacker may cause a denial of service situation of the webserver of the affected product.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Allocation of Resources Without Limits or Throttling
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
How developers prevent this class of flaw
- Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
- Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Allocation of Resources Without Limits or Throttling vulnerabilities (CWE-770)
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
Other references
Other vulnerabilities in SIMATIC CP 1242-7 V2
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 10.0 Critical severity
Recent Allocation of Resources Without Limits or Throttling vulnerabilities
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- 7.5 High severity
- 8.6 High severity
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