PCRE problem with some security policy rules

["clemence.roulin--- via Snort-users" <snort-users () lists snort org>]

Hello, I'm using Snort 2.9.13 on Centos7 with the registered Talos rules. With the default rules, Snort runs just fine 
but didn't raise many alerts so we decided to switch to the security-ips policy. When using the rules from this policy, 
Snort fails to start, displaying errors always linked to PCRE. Here is an example of what Snort says (shortened):     
snort -d -l /var/log/snort/ -c /etc/snort/snort.conf -k none Running in IDS mode   --== Initializing Snort ==-- 
Initializing Output Plugins! Initializing Preprocessors! Initializing Plug-ins! Parsing Rules file 
"/etc/snort/snort.conf" ... ... ... Reputation config: WARNING: Can't find any whitelist/blacklist entries. Reputation 
Preprocessor disabled.   +++++++++++++++++++++++++++++++++++++++++++++++++++ Initializing rule chains... ERROR: 
/etc/snort/rules/exploit-kit.rules(130) : pcre compile of "?java=[0-9]{2,6}$" failed at offset 0 : nothing to repeat 
Fatal Error, Quitting..       The rule in question, from exploit-kit.rules : alert tcp $EXTERNAL_NET $HTTP_PORTS -> 
$HOME_NET any (msg:"BROWSER-WEBKIT WebKit button column memory corruption attempt"; flow:to_ client,established; 
file_data; content:"-webkit-column-span"; fast_pattern; nocase; content:"document.documentElement.offsetTop"; d 
istance:0; 
pcre:"/(functions+(?P<function>[a-z0-9_-]+)()s*{.*?(?P<div>[a-z0-9_-]+)s*=s*document.createElement('div')x3b.*?(?P=div).
 
style['-webkit-column-span']s*=s*'all'x3b.*?document.getElementById("(?P<button>[a-z0-9_-]+)").appendChild((?P=div))x3b.*?document.
 
documentElement.offsetTopx3b.*?<body[^>]*?onloads*=s*"(?P=function)()"[^>]*?>.*?<button[^>]*?ids*=s*"(?P=button)"[^>]*?styles*=s*"[
 
^"]*?-webkit-column-widthx3a1px"[^>]*?>)|(<style>.*?{s*-webkit-column-spanx3as*allx3b.*?functions+(?P<function2>[a-z0-9_-]+)()s*{.*
 
?(?P<div2>[a-z0-9_-]+)*s*=s*document.createElement('div')x3b.*?(?P<button2>[a-z0-9_-]+)s*=s*document.createElement('button')x3b.*?d
 
ocument.documentElement.appendChild((?P=button2))x3b.*?(?P=button2).appendChild((?P=div2)).*?document.documentElement.offsetTopx3b)
 /smi"; metadata:policy max-detect-ips drop, policy security-ips drop, service http; reference:bugtraq,54680; 
reference:cve,2012-152 0; classtype:attempted-user; sid:23805; rev:8;)   I had PCRE 8.32 when it started, so updated it 
to PCRE 8.43 which seemed to be the most recent version, but the errors remain. I have put it through pcretest, and 
have the same error so the problem definitely comes from the PCRE pattern and not any other part of the rules. I have 
downloaded the rules directly from the snort.org website, and tried to download it again to check if it wasn't due to 
the file being corrupted while downloaded, but it's not. I tried to comment out this rule, but many more have similar 
problems, for example this other rule where the PCRE parser fails, also from exploit-kit.rules : alert tcp $HOME_NET 
any -> $EXTERNAL_NET $HTTP_PORTS (msg:"EXPLOIT-KIT Whitehole exploit kit malicious jar download attempt"; flow: 
to_server,established; content:"?java="; fast_pattern:only; http_uri; pcre:"/?java=[0-9]{2,6}$/U"; 
flowbits:set,file.exploit_kit.ja r; metadata:impact_flag red, policy balanced-ips drop, policy max-detect-ips drop, 
policy security-ips drop, service http; referenc e:cve,2011-3544; reference:cve,2012-1723; reference:cve,2012-4681; 
reference:cve,2012-5076; reference:cve,2013-0422; reference:cve, 2013-1493; reference:cve,2013-2423; 
reference:url,malware.dontneedcoffee.com/2013/02/briefly-wave-whitehole-exploit-kit-hello.html; 
classtype:trojan-activity; sid:25804; rev:5; Some rules also work fine while containing PCRE patterns.   Are the weird 
rules basing their PCRE patterns on another version of PCRE ? Or is the problem somewhere else ? Thank you

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