CONPROSYS HMI System (CHS): Incorrect Permission Assignment for Critical Resource
CVE-2023-28399 is a high-severity incorrect permission assignment for critical resource vulnerability in CONPROSYS HMI System (CHS) from Contec, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected CONPROSYS HMI System (CHS) versions: versions prior to 3.5.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.18% 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 Conprosys Hmi System to 3.5.3 or a later version.
- Read the advisory on contec.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Contec | CONPROSYS HMI System (CHS) | versions prior to 3.5.3 | Not stated |
| Contec | Conprosys Hmi System | before 3.5.3 | 3.5.3 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
Incorrect permission assignment for critical resource exists in CONPROSYS HMI System (CHS) versions prior to 3.5.3. ACL (Access Control List) is not appropriately set to the local folder where the affected product is installed, therefore a wide range of privileges is permitted to a user of the PC where the affected product is installed. As a result, the user may be able to destroy the system and/or execute a malicious program.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Permission Assignment for Critical Resource
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.
How developers prevent this class of flaw
- When using a critical resource such as a configuration file, check to see if the resource has insecure permissions (such as being modifiable by any regular user), and generate an error or even exit the software if there is a possibility that the resource could have been modified by an unauthorized party.
- Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully defining distinct user groups, privileges, and/or roles. Map these against data, functionality, and the related resources. Then set the permissions accordingly. This will allow you to maintain more fine-grained control over your resources.
- During program startup, explicitly set the default permissions or umask to the most restrictive setting possible. Also set the appropriate permissions during program installation. This will prevent you from inheriting insecure permissions from any user who installs or runs the program.
More Incorrect Permission Assignment for Critical Resource vulnerabilities (CWE-732)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- jvn.jp/en/vu/JVNVU93372935/Third Party Advisory
Other vulnerabilities in CONPROSYS HMI System (CHS)
- 8.8 High severity
- 7.5 High severity
- 7.2 High severity
- 8.1 High severity
- 8.8 High severity
- 7.5 High severity
Recent Incorrect Permission Assignment for Critical Resource vulnerabilities
- 7.3 High severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
- 8.8 High severity
- 8.8 High severity
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