CVE-2019-5023: Opensrcsec Grsecurity

Medium severity, CVSS 5.9. EPSS: 0.7% chance of exploitation in the next 30 days.

An exploitable vulnerability exists in the grsecurity PaX patch for the function read_kmem, in PaX from version pax-linux-4.9.8-test1 to 4.9.24-test7, grsecurity official from version grsecurity-3.1-4.9.8-201702060653 to grsecurity-3.1-4.9.24-201704252333, grsecurity unofficial from version v4.9.25-unofficialgrsec to v4.9.74-unofficialgrsec. PaX adds a temp buffer to the read_kmem function, which is never freed when an invalid address is supplied. This results in a memory leakage that can lead to a crash of the system. An attacker needs to induce a read to /dev/kmem using an invalid address to exploit this vulnerability.

Affected products

• Opensrcsec Grsecurity: from 3.1-4.9.8-201702060653, up to and including 3.1-4.9.24-201704252333; from 4.9.25, up to and including 4.9.74
• Opensrcsec Pax: from pax-linux-4.9.8-test1, up to and including pax-linux-4.9.8-test7

Published 2019-10-31. Last modified 2026-06-17.