Sysmac Cs1 Firmware: Improper Verification of Cryptographic Signature
CVE-2022-31207 is a critical-severity improper verification of cryptographic signature vulnerability in Sysmac Cs1 Firmware from Omron, with a CVSS 3.1 base score of 9.8 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 4.1 as the first without the flaw, so updating Sysmac Cs1 Firmware 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.
Critical severity: a successful attack would have severe impact.
What to do
- Update Sysmac Cs1 Firmware to 4.1 or a later version.
- Update Sysmac Cj2m Firmware to 2.1 or a later version.
- Update Sysmac Cj2h Firmware to 1.5 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 |
|---|---|---|---|
| Omron | Sysmac Cs1 Firmware | before 4.1 | 4.1 |
| Omron | Sysmac Cj2m Firmware | before 2.1 | 2.1 |
| Omron | Sysmac Cj2h Firmware | before 1.5 | 1.5 |
| Omron | Sysmac Cp1e Firmware | before 1.30 | 1.30 |
| Omron | Sysmac Cp1h Firmware | before 1.30 | 1.30 |
| Omron | Sysmac Cp1l Firmware | before 1.10 | 1.10 |
| Omron | Cp1w-cif41 Firmware | Not specified in the record | Not stated |
Version data comes from NVD's product matching. 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
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
The Omron SYSMAC Cx product family PLCs (CS series, CJ series, and CP series) through 2022-05-18 lack cryptographic authentication. They utilize the Omron FINS (9600/TCP) protocol for engineering purposes, including downloading projects and control logic to the PLC. This protocol has authentication flaws as reported in FSCT-2022-0057. Control logic is downloaded to PLC volatile memory using the FINS Program Area Read and Program Area Write commands or to non-volatile memory using other commands from where it can be loaded into volatile memory for execution. The logic that is loaded into and executed from the user program area exists in compiled object code form. Upon execution, these object codes are first passed to a dedicated ASIC that determines whether the object code is to be executed by the ASIC or the microprocessor. In the former case, the object code is interpreted by the ASIC whereas in the latter case the object code is passed to the microprocessor for object code interpretation by a ROM interpreter. In the abnormal case where the object code cannot be handled by either, an abnormal condition is triggered and the PLC is halted. The logic that is downloaded to the PLC does not seem to be cryptographically authenticated, thus allowing an attacker to manipulate transmitted object code to the PLC and either execute arbitrary object code commands on the ASIC or on the microprocessor interpreter.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Verification of Cryptographic Signature
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
More Improper Verification of Cryptographic Signature vulnerabilities (CWE-347)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cisa.gov/uscert/ics/advisories/icsa-22-179-02Third Party Advisory, US Government Resource
- forescout.com/blog/Third Party Advisory
Other vulnerabilities in Sysmac Cs1 Firmware
- 7.5 High severity
- 7.5 High severity
Recent Improper Verification of Cryptographic Signature vulnerabilities
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
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