#49785 [NEW]: htmlspecialchars() should check byte sequence more strictly

From: hello at iwamot dot com Operating system: all PHP version: 5.3.0 PHP Bug Type: Strings related Bug description: htmlspecialchars() should check byte sequence more strictly Description: ------------ Suppose htmlspecialchars() should check byte sequence more strictly for security reasons. An XSS exploit code has been unveiled. http://d.hatena.ne.jp/t_komura/20091004/1254665511 [ja] I wrote a primitive patch. http://iwamot.com/misc/html.c.patch.20091006 I don't know whether it is useful though :) Reproduce code: --------------- // overlong UTF-8 sequence echo htmlspecialchars("A\xC0\xAF&", ENT_QUOTES, 'UTF-8'); // invalid Shift_JIS sequence echo htmlspecialchars("B\x80&", ENT_QUOTES, 'Shift_JIS'); echo htmlspecialchars("C\x81\x7f&", ENT_QUOTES, 'Shift_JIS'); // invalid EUC-JP sequence echo htmlspecialchars("D\x80&", ENT_QUOTES, 'EUC-JP'); echo htmlspecialchars("E\xA1\xFF&", ENT_QUOTES, 'EUC-JP'); echo htmlspecialchars("F\x8E\xFF&", ENT_QUOTES, 'EUC-JP'); echo htmlspecialchars("G\x8F\xA1\xFF&", ENT_QUOTES, 'EUC-JP'); Expected result: ---------------- output nothing Actual result: -------------- A_&B_&C&D_&E__&F__&G___& ("_" means an invalid byte) -- Edit bug report at http://bugs.php.net/?id=49785&edit=1 -- Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=49785&r=trysnapshot52 Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=49785&r=trysnapshot53 Try a snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=49785&r=trysnapshot60 Fixed in SVN: http://bugs.php.net/fix.php?id=49785&r=fixed Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=49785&r=needdocs Fixed in release: http://bugs.php.net/fix.php?id=49785&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=49785&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=49785&r=needscript Try newer version: http://bugs.php.net/fix.php?id=49785&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=49785&r=support Expected behavior: http://bugs.php.net/fix.php?id=49785&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=49785&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=49785&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=49785&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=49785&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=49785&r=dst IIS Stability: http://bugs.php.net/fix.php?id=49785&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=49785&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=49785&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=49785&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=49785&r=mysqlcfg