ext/mysqlnd/mysqlnd_wireprotocol.c in PHP before 5.6.26 and 7.x before 7.0.11 does not verify that a BIT field has the UNSIGNED_FLAG flag, which allows remote MySQL servers to cause a denial of service (heap-based buffer overflow) or possibly have unspecified other impact via crafted field metadata.
http://www.openwall.com/lists/oss-security/2016/09/15/10
http://www.php.net/ChangeLog-5.php
http://www.php.net/ChangeLog-7.php
http://www.securityfocus.com/bid/93005
http://www.securitytracker.com/id/1036836
https://access.redhat.com/errata/RHSA-2018:1296
https://bugs.php.net/bug.php?id=72293
https://github.com/php/php-src/commit/28f80baf3c53e267c9ce46a2a0fadbb981585132?w=1
Source: MITRE
Published: 2016-09-17
Updated: 2018-05-04
Type: CWE-119
Base Score: 6.8
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 8.1
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 2.2
Severity: HIGH