In PHP before 5.6.31, 7.x before 7.0.21, and 7.1.x before 7.1.7, the openssl extension PEM sealing code did not check the return value of the OpenSSL sealing function, which could lead to a crash of the PHP interpreter, related to an interpretation conflict for a negative number in ext/openssl/openssl.c, and an OpenSSL documentation omission.
git.php.net/?p=php-src.git%3Ba=commit%3Bh=73cabfedf519298e1a11192699f44d53c529315e
git.php.net/?p=php-src.git%3Ba=commit%3Bh=89637c6b41b510c20d262c17483f582f115c66d6
git.php.net/?p=php-src.git%3Ba=commit%3Bh=91826a311dd37f4c4e5d605fa7af331e80ddd4c3
openwall.com/lists/oss-security/2017/07/10/6
php.net/ChangeLog-5.php
php.net/ChangeLog-7.php
access.redhat.com/errata/RHSA-2018:1296
bugs.php.net/bug.php?id=74651
security.netapp.com/advisory/ntap-20180112-0001/
www.debian.org/security/2018/dsa-4080
www.debian.org/security/2018/dsa-4081
www.tenable.com/security/tns-2017-12