Commit 013f84
2026-11-12 12:27:47 flichtenheld: -/-| /dev/null .. Security Announcements/CVE-2026-121720.md | |
| @@ 0,0 1,19 @@ | |
| + | # CVE-2026-121720 - Windows: Interactive service passes user environment to openvpn.exe |
| + | |
| + | In OpenVPN on Windows, `RunOpenvpn()` in the Windows Interactive Service created the child process environment block for openvpn.exe from the full environment of the requesting user. This included variables the user defined in `HKCU\Environment`. |
| + | |
| + | User-controlled environment variables can influence what code openvpn.exe loads and runs. For example, a user-defined `OPENSSL_CONF` variable can cause OpenSSL to load provider modules. Because the resulting openvpn.exe process has access to privileged operations through the `--msg-channel` connection to the service, a local user could run code of their choice inside the OpenVPN process and use that process to request privileged service operations. |
| + | |
| + | The fix changes the service to build the environment for openvpn.exe from system-wide variables, while only copying a small allowlist of user-specific variables from the user's environment: `APPDATA`, `LOCALAPPDATA`, `TEMP`, `TMP`, `USERDOMAIN`, `USERNAME`, and `USERPROFILE`. Other user-defined variables are no longer passed to openvpn.exe. |
| + | |
| + | OpenVPN versions 2.4.0 through 2.7.8 are affected. This is fixed in version 2.7.9. |
| + | |
| + | CVE Record: [CVE-2026-121720](https://www.cve.org/CVERecord?id=CVE-2026-121720) |
| + | |
| + | Github: |
| + | * [OpenVPN/openvpn-private-issues#186](https://github.com/OpenVPN/openvpn-private-issues/issues/186) |
| + | |
| + | Release notes: |
| + | * [openvpn-2.7.9](https://community.openvpn.net/ReleaseHistory#openvpn-279-released-5-november-2026) |
| + | |
| + | Reported-By: @refiaa |