The private filesystem in Drupal 5.x before 5.10 and 6.x before 6.4 trusts the MIME type sent by a web browser, which allows remote authenticated users to conduct cross-site scripting (XSS) attacks by uploading files containing arbitrary web script or HTML.

References

• https://nvd.nist.gov/vuln/detail/CVE-2008-3741
• https://bugzilla.redhat.com/show_bug.cgi?id=459108
• https://exchange.xforce.ibmcloud.com/vulnerabilities/44446
• https://www.redhat.com/archives/fedora-package-announce/2008-September/msg00259.html
• https://www.redhat.com/archives/fedora-package-announce/2008-September/msg00508.html
• http://drupal.org/node/295053
• http://secunia.com/advisories/31462
• http://secunia.com/advisories/31825
• http://www.securityfocus.com/bid/30689
• http://www.vupen.com/english/advisories/2008/2392