OpenVPN: Incorrect Default Permissions
CVE-2023-7235 is a high-severity incorrect default permissions vulnerability in OpenVPN, with a CVSS 3.1 base score of 8.4 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. Affected OpenVPN versions: 2.6.8 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.21% 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 Openvpn Gui to 2.6.9 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| OpenVPN | OpenVPN | 2.6.8 and earlier | Not stated |
| Openvpn | Openvpn Gui | before 2.6.9 | 2.6.9 |
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
- 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:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
The OpenVPN GUI installer before version 2.6.9 did not set the proper access control restrictions to the installation directory of OpenVPN binaries when using a non-standard installation path, which allows an attacker to replace binaries to run arbitrary executables.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Default Permissions
During installation, installed file permissions are set to allow anyone to modify those files.
How developers prevent this class of flaw
- The architecture needs to access and modification attributes for files to only those users who actually require those actions.
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
More Incorrect Default Permissions vulnerabilities (CWE-276)
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
Other references
- community.openvpn.net/openvpn/wiki/CVE-2023-7235Permissions Required
Other vulnerabilities in OpenVPN
- 7.2 High severity
- 7.1 High severity
- 8.7 High severity
- 7.7 High severity
- 8.5 High severity
- 9.1 Critical severity
Recent Incorrect Default Permissions vulnerabilities
- 8.4 High severity
- 7.8 High severity
- 7.3 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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