The function `read_data()` in security.c in curl before version 7.51.0 is vulnerable to memory double free.Referenceshttps://curl.haxx.se/docs/adv_20161102E.htmlhttps://access.redhat.com/errata/RHSA-2018:3558https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-8619https://curl.haxx.se/CVE-2016-8619.patchhttp://www.securityfocus.com/bid/94100https://www.tenable.com/security/tns-2016-21http://www.securitytracker.com/id/1037192http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.htmlhttps://access.redhat.com/errata/RHSA-2018:2486https://security.gentoo.org/glsa/201701-47