Description
The modprobe child process in the ./debian/patches/load_ppp_generic_if_needed patch file incorrectly handled module loading. A local non-root attacker could exploit the MODPROBE_OPTIONS environment variable to read arbitrary root files. Fixed in 2.4.5-5ubuntu1.4, 2.4.5-5.1ubuntu2.3+esm2, 2.4.7-1+2ubuntu1.16.04.3, 2.4.7-2+2ubuntu1.3, 2.4.7-2+4.1ubuntu5.1, 2.4.7-2+4.1ubuntu6. Was ZDI-CAN-11504.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Canonical | ppp | 2.4.5 – < 2.4.5-5ubuntu1.4, 2.4.7 – < 2.4.7-1+2ubuntu1.16.04.3 | 2.4.5-5ubuntu1.4 |
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.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | ppp | 2.4.7-2+4.1ubuntu5.1 | USN-4451-1 |
| Ubuntu 18.04 LTS | ppp | 2.4.7-2+2ubuntu1.3 | USN-4451-1 |
| Ubuntu 16.04 LTS | ppp | 2.4.7-1+2ubuntu1.16.04.3 | USN-4451-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | ppp | 2.4.5-5.1ubuntu2.3+esm2 | USN-4451-2 |
Advisories 2
- USN-4451-2 ppp vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-4451-1 ppp vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
References
- https://ubuntu.com/security/notices/USN-4451-1 vendor-advisory
- https://ubuntu.com/security/notices/USN-4451-2 vendor-advisory