Bug #70480 [Fbk]: php_url_parse_ex() buffer overflow read

Edit report at https://bugs.php.net/bug.php?id=70480&edit=1 ID: 70480 Updated by: yohgaki@php.net Reported by: yohgaki@php.net Summary: php_url_parse_ex() buffer overflow read Status: Feedback Type: Bug Package: URL related Operating System: Irrelevant PHP Version: Irrelevant Assigned To: yohgaki Block user comment: N Private report: N New Comment: For example, when smart_str is used, a code may assume php_url_prase_ex() operates up to "length". The smart_str may not have terminating null char because it could be work in progress string. However, strchr() looks for terminating null char, but smart_str may not have terminating null char. If this is the case, buffer overread happens and PHP crashes. Anyway, php_url_prase_ex() is supposed to be binary safe as it has "length" parameter, but it isn't due to the strchr(). Previous Comments: ------------------------------------------------------------------------ [2015-09-26 08:06:23] stas@php.net Could you add an example when the buffer overflow/segfault happens? ------------------------------------------------------------------------ [2015-09-13 06:34:15] yohgaki@php.net Description: ------------ php_url_prase_ex() read buffer exceeding its limits and segfaults. PHP function parse_url() is not affected since PHP string is terminated by null char always. Patch to fix this: @@ -319,8 +320,9 @@ PHPAPI php_url *php_url_parse_ex(char const *str, size_t length) nohost: if ((p = memchr(s, '?', (ue - s)))) { - pp = strchr(s, '#'); + pp = memchr(s, '#', (ue - s)); if (pp && pp < p) { if (pp - s) { Test script: --------------- N/A This bug only appears only when php_url_prase_ex() is called internally. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=70480&edit=1