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

ID: 49785 Comment by: mcdmaster at auone dot jp Reported By: hello at iwamot dot com Status: Assigned Bug Type: Strings related Operating System: * PHP Version: 5.3.0 Assigned To: moriyoshi New Comment: I agree with Iwamot. Jani seems that he's reluctant for all the CJK-related issues, though this issue specifically makes not only CJK users but also all the UTF-8 people suffer security damages e.g. XSS exploits with invalid character code(s) injected. It's obvious for Jani to do mix-up between this issue and the bug #43896, which is supposed as duplicated as he insists. I'm sure that he should recognize that each of those issues is entirely apart, even though its fundamental cause were the same. The patch that Iwamot has provided should be reviewed ASAP and made official. Thank you Iwamot! Previous Comments: ------------------------------------------------------------------------ [2009-10-09 05:46:09] moriyoshi@php.net This is a valid bug IMO. ------------------------------------------------------------------------ [2009-10-06 19:51:56] hello at iwamot dot com If #43896, Jani's comment doesn't make sense. I suppose that you developers can change htmlspecialchars() to be more STRICT. ------------------------------------------------------------------------ [2009-10-06 12:38:05] hello at iwamot dot com Could you tell me the report number? ------------------------------------------------------------------------ [2009-10-06 12:12:24] jani@php.net Please do not submit the same bug more than once. An existing bug report already describes this very problem. Even if you feel that your issue is somewhat different, the resolution is likely to be the same. Thank you for your interest in PHP. ------------------------------------------------------------------------ [2009-10-06 11:40:05] hello at iwamot dot com 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 this bug report at http://bugs.php.net/?id=49785&edit=1