file/edit_html.cgi in Webmin 1.590 and earlier does not perform an authorization check before showing a file’s unedited contents, which allows remote attackers to read arbitrary files via the file field.
americaninfosec.com/research/index.html
www.americaninfosec.com/research/dossiers/AISG-12-002.pdf
www.kb.cert.org/vuls/id/788478
www.securitytracker.com/id?1027507
www.xerox.com/download/security/security-bulletin/16287-4d6b7b0c81f7b/cert_XRX13-003_v1.0.pdf
github.com/webmin/webmin/commit/4cd7bad70e23e4e19be8ccf7b9f245445b2b3b80