The process_envvars function in elf/rtld.c in the GNU C Library (aka glibc or libc6) before 2.23 allows local users to bypass a pointer-guarding protection mechanism via a zero value of the LD_POINTER_GUARD environment variable.
http://hmarco.org/bugs/glibc_ptr_mangle_weakness.html
http://lists.fedoraproject.org/pipermail/package-announce/2016-February/177404.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00036.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00037.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00038.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00039.html
http://www.debian.org/security/2016/dsa-3480
http://www.openwall.com/lists/oss-security/2016/01/20/1
http://www.securityfocus.com/bid/81469
http://www.securitytracker.com/id/1034811
http://www.ubuntu.com/usn/USN-2985-1
http://www.ubuntu.com/usn/USN-2985-2
https://access.redhat.com/errata/RHSA-2017:1916
Source: MITRE
Published: 2016-01-20
Updated: 2018-01-05
Type: CWE-254
Base Score: 2.1
Vector: AV:L/AC:L/Au:N/C:N/I:P/A:N
Impact Score: 2.9
Exploitability Score: 3.9
Severity: LOW
Base Score: 5.5
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Impact Score: 3.6
Exploitability Score: 1.8
Severity: MEDIUM