CJ-series and CS-series CPU modules: Improper Restriction of Excessive Authentication Attempts
CVE-2022-45790 is a critical-severity improper restriction of excessive authentication attempts vulnerability in CJ-series and CS-series CPU modules from Omron, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 1.5, 2.1, 4.1 as the first without the flaw, so updating CJ-series and CS-series CPU modules to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.91% chance of exploitation within 30 days, higher than 60% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update CJ-series and CS-series CPU modules to 1.5 or 2.1 or 4.1 or 1.4, whichever matches your release line, or a later version.
- Update Cj1g-cpu45p Firmware to 4.1 or a later version.
- Update Cj1g-cpu45p-gtc Firmware to 4.1 or a later version.
- Read the advisory on fa.omron.co.jp 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Omron | CJ-series and CS-series CPU modules | CJ2H 0.0 up to, but not including, 1.5; CJ2M 0.0 up to, but not including, 2.1; CJ1G 0.0 up to, but not including, 4.1; CS1H 0.0 up to, but not including, 4.1; CS1G 0.0 up to, but not including, 4.1; CS1D-H 0.0 up to, but not including, 1.4; CP1E-E 0.0 up to, but not including, 1.3; CP1E-N 0.0 up to, but not including, 1.3; and 1 more ranges | 1.5, 2.1, 4.1, 1.4, 1.3 |
| Omron | Cj1g-cpu45p Firmware | before 4.1 | 4.1 |
| Omron | Cj1g-cpu45p-gtc Firmware | before 4.1 | 4.1 |
| Omron | Cj1g-cpu44p Firmware | before 4.1 | 4.1 |
| Omron | Cj1g-cpu43p Firmware | before 4.1 | 4.1 |
| Omron | Cj1g-cpu42p Firmware | before 4.1 | 4.1 |
| Omron | Cp1e-e Firmware | before 1.3 | 1.3 |
| Omron | Cp1e-n Firmware | before 1.3 | 1.3 |
| Omron | Cj2h-cpu68 Firmware | before 1.5 | 1.5 |
| Omron | Cj2h-cpu67 Firmware | before 1.5 | 1.5 |
| Omron | Cj2h-cpu66 Firmware | before 1.5 | 1.5 |
| Omron | Cj2h-cpu65 Firmware | before 1.5 | 1.5 |
| Omron | Cj2h-cpu64 Firmware | before 1.5 | 1.5 |
| Omron | Cj2h-cpu68-eip Firmware | before 1.5 | 1.5 |
| Omron | Cj2h-cpu67-eip Firmware | before 1.5 | 1.5 |
| Omron | Cj2h-cpu66-eip Firmware | before 1.5 | 1.5 |
| Omron | Cj2h-cpu65-eip Firmware | before 1.5 | 1.5 |
| Omron | Cj2h-cpu64-eip Firmware | before 1.5 | 1.5 |
| Omron | Cj2m-cpu35 Firmware | before 2.1 | 2.1 |
| Omron | Cj2m-cpu34 Firmware | before 2.1 | 2.1 |
| Omron | Cj2m-cpu33 Firmware | before 2.1 | 2.1 |
| Omron | Cj2m-cpu32 Firmware | before 2.1 | 2.1 |
| Omron | Cj2m-cpu31 Firmware | before 2.1 | 2.1 |
| Omron | Cj2m-cpu15 Firmware | before 2.1 | 2.1 |
| Omron | Cj2m-cpu14 Firmware | before 2.1 | 2.1 |
Version data comes from the organisation that assigned the CVE; 22 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
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.6 | High | CNA (dragos.com) |
| CVSS 3.1 | 9.1 | Critical | NVD |
Official description
The Omron FINS protocol has an authenticated feature to prevent access to memory regions. Authentication is susceptible to bruteforce attack, which may allow an adversary to gain access to protected memory. This access can allow overwrite of values including programmed logic.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Restriction of Excessive Authentication Attempts
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
How developers prevent this class of flaw
- Common protection mechanisms include: Disconnecting the user after a small number of failed attempts Implementing a timeout Locking out a targeted account Requiring a computational task on the user's part.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
More Improper Restriction of Excessive Authentication Attempts vulnerabilities (CWE-307)
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
Third-party and government advisories
- cisa.gov/news-events/ics-advisories/icsa-23-262-05Third Party Advisory, US Government Resource
- dragos.com/advisory/omron-plc-and-engineering-software-network-and-file-format-access/Third Party Advisory
Other vulnerabilities in CJ-series and CS-series CPU modules
- 7.5 High severity
Recent Improper Restriction of Excessive Authentication Attempts vulnerabilities
- 9.1 Critical severity
- 8.1 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.1 Critical severity
- 9.8 Critical severity
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