ifm Smart PLC AC402s: Missing Authentication for Critical Functionality
CVE-2024-8419 is a high-severity missing authentication for critical functionality vulnerability in ifm Smart PLC AC402s from Ifm Electronic, 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 4.3.17 as the first without the flaw, so updating ifm Smart PLC AC402s to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.48% 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 ifm Smart PLC AC402s to 4.3.17 or a later version.
- Update ifm Smart PLC AC422s to 4.3.17 or a later version.
- Update ifm Smart PLC AC424s to 4.3.17 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 |
|---|---|---|---|
| Ifm Electronic | ifm Smart PLC AC402s | 4.04 up to, but not including, 4.3.17; 6.1.8 | 4.3.17 |
| Ifm Electronic | ifm Smart PLC AC422s | 4.04 up to, but not including, 4.3.17; 6.1.8 | 4.3.17 |
| Ifm Electronic | ifm Smart PLC AC424s | 4.04 up to, but not including, 4.3.17; 6.1.8 | 4.3.17 |
| Ifm Electronic | ifm Smart PLC AC432s | 4.04 up to, but not including, 4.3.17; 6.1.8 | 4.3.17 |
| Ifm Electronic | ifm Smart PLC AC434s | 4.04 up to, but not including, 4.3.17; 6.1.8 | 4.3.17 |
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (cert.vde.com).
Official description
The endpoint hosts a script that allows an unauthorized remote attacker to put the system in a fail-safe state over the network due to missing authentication.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authentication for Critical Functionality
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
How developers prevent this class of flaw
- 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.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
- When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.
More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)
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
Recent Missing Authentication for Critical Functionality vulnerabilities
- 9.8 Critical severity
- 8.1 High severity
- 9.8 Critical severity
- 7.5 High severity
- 8.2 High severity
- 9.6 Critical severity
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