On the x86-64 architecture, the GNU C Library (aka glibc) before 2.31 fails to ignore the LD_PREFER_MAP_32BIT_EXEC environment variable during program execution after a security transition, allowing local attackers to restrict the possible mapping addresses for loaded libraries and thus bypass ASLR for a setuid program.
| Software | From | Fixed in |
|---|---|---|
| gnu / glibc | - | 2.31 |
| canonical / ubuntu_linux | 18.04 | 18.04.x |
| canonical / ubuntu_linux | 19.10 | 19.10.x |
| canonical / ubuntu_linux | 16.04 | 16.04.x |
| fedoraproject / fedora | 30 | 30.x |
| fedoraproject / fedora | 31 | 31.x |
| debian / debian_linux | 10.0 | 10.0.x |