Ejegg has uploaded a new change for review. (
https://gerrit.wikimedia.org/r/391416 )
Change subject: SECURITY: Handle -{}- syntax in attributes safely
......................................................................
SECURITY: Handle -{}- syntax in attributes safely
Previously, if one had an attribute with the contents
"-{}-foo-{}-", foo would get replaced by language converter as if
it wasn't in an attribute. This lead to an XSS attack.
This breaks doing manual conversions in url href's (or any
other attribute that goes through an escaping method
other than Sanitizer's). e.g. http://{sr-el:foo';sr-ec:bar}.com
won't work anymore. See also T87332
Bug: T119158
Change-Id: Idbc45cac12c309b0ccb4adeff6474fa527b48edb
---
M languages/LanguageConverter.php
M tests/parser/parserTests.txt
2 files changed, 39 insertions(+), 10 deletions(-)
git pull ssh://gerrit.wikimedia.org:29418/mediawiki/core
refs/changes/16/391416/1
diff --git a/languages/LanguageConverter.php b/languages/LanguageConverter.php
index 4200978..87eb80d 100644
--- a/languages/LanguageConverter.php
+++ b/languages/LanguageConverter.php
@@ -377,9 +377,12 @@
$scriptfix =
'<script[^>]*+>[^<]*+(?:(?:(?!<\/script>).)[^<]*+)*+<\/script>|';
// disable conversion of <pre> tags
$prefix =
'<pre[^>]*+>[^<]*+(?:(?:(?!<\/pre>).)[^<]*+)*+<\/pre>|';
+ // The "|.*+)" at the end, is in case we missed some part of
html syntax,
+ // we will fail securely (hopefully) by matching the rest of
the string.
+ $htmlFullTag =
'<(?:[^>=]*+(?>[^>=]*+=\s*+(?:"[^"]*"|\'[^\']*\'|[^\'">\s]*+))*+[^>=]*+>|.*+)|';
- $reg = '/' . $codefix . $scriptfix . $prefix .
- '<[^>]++>|&[a-zA-Z#][a-z0-9]++;' . $marker . $htmlfix .
'|\004$/s';
+ $reg = '/' . $codefix . $scriptfix . $prefix . $htmlFullTag .
+ '&[a-zA-Z#][a-z0-9]++;' . $marker . $htmlfix .
'|\004$/s';
$startPos = 0;
$sourceBlob = '';
$literalBlob = '';
@@ -660,29 +663,41 @@
$out = '';
$length = strlen( $text );
$shouldConvert = !$this->guessVariant( $text, $variant );
+ $continue = 1;
- while ( $startPos < $length ) {
- $pos = strpos( $text, '-{', $startPos );
+ $noScript = '<script.*?>.*?<\/script>(*SKIP)(*FAIL)';
+ $noStyle = '<style.*?>.*?<\/style>(*SKIP)(*FAIL)';
+ $noHtml =
'<(?:[^>=]*+(?>[^>=]*+=\s*+(?:"[^"]*"|\'[^\']*\'|[^\'">\s]*+))*+[^>=]*+>|.*+)(*SKIP)(*FAIL)';
+ while ( $startPos < $length && $continue ) {
+ $continue = preg_match(
+ // Only match -{ outside of html.
+ "/$noScript|$noStyle|$noHtml|-\{/",
+ $text,
+ $m,
+ PREG_OFFSET_CAPTURE,
+ $startPos
+ );
- if ( $pos === false ) {
+ if ( !$continue ) {
// No more markup, append final segment
$fragment = substr( $text, $startPos );
$out .= $shouldConvert ? $this->autoConvert(
$fragment, $variant ) : $fragment;
return $out;
}
- // Markup found
+ // Offset of the match of the regex pattern.
+ $pos = $m[0][1];
+
// Append initial segment
$fragment = substr( $text, $startPos, $pos - $startPos
);
$out .= $shouldConvert ? $this->autoConvert( $fragment,
$variant ) : $fragment;
-
- // Advance position
+ // -{ marker found, not in attribute
+ // Advance position up to -{ marker.
$startPos = $pos;
-
// Do recursive conversion
+ // Note: This passes $startPos by reference, and
advances it.
$out .= $this->recursiveConvertRule( $text, $variant,
$startPos, $depth + 1 );
}
-
return $out;
}
diff --git a/tests/parser/parserTests.txt b/tests/parser/parserTests.txt
index 0838f82..4a52c46 100644
--- a/tests/parser/parserTests.txt
+++ b/tests/parser/parserTests.txt
@@ -16763,6 +16763,20 @@
!! end
!! test
+Language converter glossary rules inside attributes (T119158)
+!! options
+language=sr variant=sr-el
+!! wikitext
+-{H|abc=>sr-el:" onload="alert(1)" data-foo="}-
+
+[[File:Foobar.jpg|alt=-{}-abc-{}-]]
+!! html
+<p>
+</p><p><a
href="/wiki/%D0%94%D0%B0%D1%82%D0%BE%D1%82%D0%B5%D0%BA%D0%B0:Foobar.jpg"
class="image"><img alt="" onload="alert(1)" data-foo=""
src="http://example.com/images/3/3a/Foobar.jpg"; width="1941" height="220"></a>
+</p>
+!! end
+
+!! test
Self closed html pairs (bug 5487)
!! options
!! wikitext
--
To view, visit https://gerrit.wikimedia.org/r/391416
To unsubscribe, visit https://gerrit.wikimedia.org/r/settings
Gerrit-MessageType: newchange
Gerrit-Change-Id: Idbc45cac12c309b0ccb4adeff6474fa527b48edb
Gerrit-PatchSet: 1
Gerrit-Project: mediawiki/core
Gerrit-Branch: fundraising/REL1_27
Gerrit-Owner: Ejegg <ej...@ejegg.com>
Gerrit-Reviewer: Brian Wolff <bawolff...@gmail.com>
_______________________________________________
MediaWiki-commits mailing list
MediaWiki-commits@lists.wikimedia.org
https://lists.wikimedia.org/mailman/listinfo/mediawiki-commits
![http://example.com/images/3/3a/Foobar.jpg"](http://example.com/images/3/3a/Foobar.jpg"){kind=link}