Description
rtapi_app in linuxcnc-uspace in LinuxCNC before 2.9.9 allows privilege escalation. It is installed SUID root and loads shared library modules via dlopen() by using a user-supplied module name. Insufficient validation of the module name allows path traversal, enabling an unprivileged local user to load an arbitrary shared library. Because the process retains elevated privileges during module loading, this results in local privilege escalation to root.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| LinuxCNC | LinuxCNC | < 2.9.9 | 2.9.9 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 13 | linuxcnc | 1:2.9.4-2+deb13u1 | — |
| Debian 12 | linuxcnc | 2.9.0~pre1+git20230208.f1270d6ed7-1+deb12u2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | linuxcnc | No fix yet | — |
| Ubuntu 26.04 LTS | linuxcnc | No fix yet | — |
| Ubuntu 25.10 | linuxcnc | No fix yet | — |