The (1) mbed_connect_step1 function in lib/vtls/mbedtls.c and (2) polarssl_connect_step1 function in lib/vtls/polarssl.c in cURL and libcurl before 7.49.0, when using SSLv3 or making a TLS connection to a URL that uses a numerical IP address, allow remote attackers to spoof servers via an arbitrary valid certificate.
www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
www.securityfocus.com/bid/90726
www.securitytracker.com/id/1035907
www.slackware.com/security/viewer.php?l=slackware-security&y=2016&m=slackware-security.495349
curl.haxx.se/changes.html
curl.haxx.se/CVE-2016-3739.patch
curl.haxx.se/docs/adv_20160518.html
h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05320149
h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05390722
security.gentoo.org/glsa/201701-47