SafeHTML is anti-XSS HTML parser, written in PHP.
written and distributed under the BSD License
This parser strips down all potentially dangerous content within HTML:
- opening tag without its closing tag
- closing tag without its opening tag
- any of these tags: “base”, “basefont”, “head”, “html”, “body”, “applet”, “object”,
“iframe”, “frame”, “frameset”, “script”, “layer”, “ilayer”, “embed”, “bgsound”,
“link”, “meta”, “style”, “title”, “blink”, “xml” etc.
- any of these attributes: on*, data*, dynsrc
- expression/behavior etc. in styles
- any other active content
It also tries to convert code to XHTML valid, but htmltidy is far better solution for this task.
- added HTML5 Block-level elements
- Replaced preg_replace() e modifier with preg_replace_callback
- UTF-7 XSS vulnerability fixed
- Added 'dl' to the list of 'lists' tags.
- Added 'callto' to the white list of protocols.
- Added white list of "namespaced" attributes.
- More accurate UTF-7 decoding.
- Two serious security flaws fixed: UTF-7 XSS and CSS comments handling.
- Security flaw (improper quotes handling in attributes' values) fixed. Big thanks to Nick Cleaton.
- Dumb bug fixed (some closing tags were ignored).
- Two holes (with decimal HTML entities and with \x00 symbol) fixed.
- Class rewritten under PEAR coding standarts.
- Class now uses unmodified HTMLSax3 from PEAR.
- To the list of table tags added: "caption", "col", "colgroup".
- It was possible to create XSS with hexadecimal HTML entities. Fixed. Big thanks to Christian Stocker.
- New method parse() allows to do all parsing process in two lines of code. Examples also updated.
- New array, closeParagraph, contains list of block-level elements. When we open such elemet, we should close paragraph before.. It allows SafeHTML to produce more XHTML compliant code.
- Added "webcal" to white list of protocols for those who uses calendar programs (Mozilla/iCal/etc).
- Now SafeHTML strips down table elements when we are not inside table.
- Now SafeHTML correctly closes unclosed "li" tags: before opening "li" of the same nesting level.
- New "dangerous" protocols: hcp, ms-help, help, disk, vnd.ms.radio, opera, res, resource, chrome, mocha, livescript.
- <XML> tag was moved from "tags for deletion" to "tags for deletion with content".
- New "dangerous" CSS instruction "include-source" (NN4 specific).
- New array, Attributes, contains list of attributes for removal. If you need to remove "id" or "name" attribute, just add it to this array.
- Now it is possible to choose between white-list and black-list filtering of protocols. Defaults are "white-list".
- For speed purposes, we now filter protocols only from these attributes: src, href, action, lowsrc, dynsrc, background, codebase.
- Opera6 XSS bug ([\xC0][\xBC]script>alert(1)[\xC0][\xBC]/script> [UTF-8] workarounded.
Thanks to shmel.
Thanks to lj user=electrocat.
Author: Roman Ivanov.
Copyrights: © 2004–2005, Roman Ivanov
© 2004–2005, Pixel-Apes
© 2004–2005, JetStyle
If you found any bugs in this parser, please inform us — Bugtracker.
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when SafeHTML will be updated.