The base64 encode function in curl before version 7.51.0 is prone to a buffer being under allocated in 32bit systems if it receives at least 1Gb as input via `CURLOPT_USERNAME`.
https://www.tenable.com/security/tns-2016-21
https://security.gentoo.org/glsa/201701-47
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-8617
https://access.redhat.com/errata/RHSA-2018:2486