Description
The Linux kernel through 5.0.7, when CONFIG_IA32_AOUT is enabled and ia32_aout is loaded, allows local users to bypass ASLR on setuid a.out programs (if any exist) because install_exec_creds() is called too late in load_aout_binary() in fs/binfmt_aout.c, and thus the ptrace_may_access() check has a race condition when reading /proc/pid/stat. NOTE: the software maintainer disputes that this is a vulnerability because ASLR for a.out format executables has never been supported
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 14 | linux | No fix yet | — |
| Debian 13 | linux | No fix yet | — |
| Debian 12 | linux | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +3 | No fix yet | — |
| Ubuntu 18.04 LTS | linux | 4.15.0-51.55 | USN-4007-1 |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1040.42 | USN-4007-1 |
| Ubuntu 18.04 LTS | linux-azure | 4.18.0-1019.19~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-gcp +1 | 4.15.0-1033.35 | USN-4007-1 |
| Ubuntu 18.04 LTS | linux-hwe | 4.18.0-21.22~18.04.1 | USN-4006-2 |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1035.35 | USN-4007-1 |
| Ubuntu 18.04 LTS | linux-oem | 4.15.0-1039.44 | USN-4007-1 |
| Ubuntu 18.04 LTS | linux-oracle | 4.15.0-1014.16 | USN-4007-1 |
| Ubuntu 18.04 LTS | linux-raspi2 | 4.15.0-1037.39 | USN-4007-1 |
| Ubuntu 18.04 LTS | linux-snapdragon | 4.15.0-1054.58 | USN-4007-1 |
| Ubuntu 16.04 LTS | linux | 4.4.0-150.176 | USN-4008-1 |
| Ubuntu 16.04 LTS | linux-aws | 4.4.0-1084.94 | USN-4008-1 |
| Ubuntu 16.04 LTS | linux-aws-hwe | 4.15.0-1040.42~16.04.1 | USN-4007-2 |
| Ubuntu 16.04 LTS | linux-azure | 4.15.0-1046.50 | — |
| Ubuntu 16.04 LTS | linux-gcp | 4.15.0-1033.35~16.04.1 | — |
| Ubuntu 16.04 LTS | linux-hwe | 4.15.0-51.55~16.04.1 | USN-4007-2 |
| Ubuntu 16.04 LTS | linux-kvm | 4.4.0-1047.53 | USN-4008-1 |
| Ubuntu 16.04 LTS | linux-oracle | 4.15.0-1014.16~16.04.1 | USN-4007-2 |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1110.118 | USN-4008-1 |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1114.119 | USN-4008-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | 4.4.0-1011.14 | — |
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-aws | 4.4.0-1054.58 | USN-4008-3 |
| Ubuntu Pro 14.04 LTS | linux-azure | 4.15.0-1059.64~14.04.1 | — |
| Ubuntu Pro 14.04 LTS | linux-lts-xenial | 4.4.0-164.192~14.04.1 | USN-4008-3 |
Advisories 5
- USN-4008-1 linux, linux-aws, linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Sep 7, 2026
- USN-4008-3 linux-lts-xenial, linux-aws vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4007-1 linux, linux-aws, linux-gcp, linux-kvm, linux-oem, linux-oracle, linux-raspi2, linux-snapdragon vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-4006-2 linux-hwe vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-4007-2 linux-aws-hwe, linux-hwe, linux-oracle vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
References
- https://www.openwall.com/lists/oss-security/2019/04/03/4
- https://www.openwall.com/lists/oss-security/2019/04/03/4/1
- 107887 vdb-entry
- [oss-security] 20190418 Re: Linux kernel < 4.8 local generic ASLR - another CVE-ID mailing-list
- [oss-security] 20190522 Re: Linux kernel < 4.8 local generic ASLR - another CVE-ID mailing-list
- USN-4007-2 vendor-advisory
- USN-4008-1 vendor-advisory
- USN-4006-1 vendor-advisory
- USN-4006-2 vendor-advisory
- USN-4007-1 vendor-advisory
- USN-4008-3 vendor-advisory
- openSUSE-SU-2019:1570 vendor-advisory