The thoughtbot paperclip gem before 4.2.2 for Ruby does not consider the content-type value during media-type validation, which allows remote attackers to upload HTML documents and conduct cross-site scripting (XSS) attacks via a spoofed value, as demonstrated by image/jpeg.
jvn.jp/en/jp/JVN83881261/index.html
jvndb.jvn.jp/jvndb/JVNDB-2015-000088
openwall.com/lists/oss-security/2015/06/19/3
github.com/thoughtbot/paperclip
github.com/thoughtbot/paperclip/commit/9aee4112f36058cd28d5fe4a006d6981bd1eda57
nvd.nist.gov/vuln/detail/CVE-2015-2963
robots.thoughtbot.com/paperclip-security-release
web.archive.org/web/20200228084907/www.securityfocus.com/bid/75304