CME-108
kptr_restrict (Kernel Pointer Restriction)
Description
Hides kernel pointer addresses from unprivileged users, denying the address leaks needed to exploit kernel vulnerabilities when KASLR is active.
CVSS Vector Impacts
| Metric | Transition | Rationale |
|---|---|---|
| Attack Complexity (AC) | L → H | Removes trivial kernel address leak vector via /proc/kallsyms |
CWE Relationships
Verification
Check kptr_restrict sysctl is 1 or 2
$ cat /proc/sys/kernel/kptr_restrict
# Expected: 1
# Expected: 1
Platform: linux
Remediation
linux
Hide kernel pointers from unprivileged users via sysctl
sysctl -w kernel.kptr_restrict=1
printf 'kernel.kptr_restrict = 1\n' > /etc/sysctl.d/99-cme-108-kptr-restrict.conf