Description
TOCTOU Race Condition vulnerability in apport allows a local attacker to escalate privileges and execute arbitrary code. An attacker may exit the crashed process and exploit PID recycling to spawn a root process with the same PID as the crashed process, which can then be used to escalate privileges. Fixed in 2.20.1-0ubuntu2.24, 2.20.9 versions prior to 2.20.9-0ubuntu7.16 and 2.20.11 versions prior to 2.20.11-0ubuntu27.6. Was ZDI-CAN-11234.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Canonical | apport | 2.20.1 – < 2.20.1-0ubuntu2.24, 2.20.9 – < 2.20.9-0ubuntu7.16, 2.20.11 – < 2.20.11-0ubuntu27.6 | 2.20.1-0ubuntu2.24 |
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 | apport | 2.20.11-0ubuntu27.6 | USN-4449-1 |
| Ubuntu 18.04 LTS | apport | 2.20.9-0ubuntu7.16 | USN-4449-1 |
| Ubuntu 16.04 LTS | apport | 2.20.1-0ubuntu2.24 | USN-4449-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | apport | 2.14.1-0ubuntu3.29+esm5 | USN-4449-2 |
Advisories 2
- USN-4449-1 apport vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-4449-2 apport vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
References
- https://usn.ubuntu.com/4449-1
- USN-4449-1 vendor-advisory
- https://www.zerodayinitiative.com/advisories/ZDI-20-979/
- USN-4449-2 vendor-advisory