View the original advisory here.
This is most probably the most funny advisory I ever published. I found some decent vulnerabilities within the code of the very popular counter “chCounter”.
It is fact a very cool counter. Simply implement the counter file into your website and view the stats in the admin backend.
>> #1 Vulnerability Type = SQL Injection This is a very untypical SQL injection vulnerability. While viewing the details of a website in the chCounter backend, some data gets selected out of the database. E. g. which pages the visitor viewed, their page titles, what user agent he got etc. The stuff gets selected and displayed directly in the admin backend. File: administrator/visitor_details.php Query: $result = $_CHC_DB->query( 'SELECT wert, titel FROM `'. CHC_TABLE_PAGES .'` WHERE '. $bedingung .' ORDER BY monat DESC' ); The script thrusts the common visitor. When you view a website which uses chCounter, the title of the current page and other information gets directly written into the table chc_pages, column "wert". When the admin views the visitor's details (which contain the title of the visited pages) in the backend, the information is selected directly, no filter is used. Basically the website's visitor only has to achieve a manipulation of the current page title. This is very easy when you think of dynamic websites like WordPress or Joomla. I tested this on a WordPress installation, so all I had to do was visiting wordpress/index.php?s=[malicious SQL commands] Since the parameter "s" is well known to WordPress, the page gets displayed (in this case also a query gets executed and the "injected" stuff gets displayed in the URL, so this would be a second possibility to inject code) and the title now changed to something like this: Search Results [malicious SQL commands] The title gets entered into the database, the admin views those details in the backend and there it is: an SQL injection. The value of the field "wert" is used in the query I showed earlier, so it is now: SELECT wert [SQL Injection], titel FROM `'. CHC_TABLE_PAGES .'` WHERE '. $bedingung .' ORDER BY monat DESC' ); The newly crafted query gets executed in the admin's backend and common stuff like dropping all tables would be possible. And the most fun part is probably that the admin is the one "hacking" his own website without even knowing that there could be danger by viewing simple stats. Since the chCounter is widly spread and available for free, an attacker could know about it's database structure. The page title is just one example, you can also manipulate the user agent or URLs. Unfortunately this is only an indirect SQL injection since the admin has to be active and look at the chCounter stats in the admin panel. Still it is fun! >> #2 Vulnerability Type = XSS This vulnerability is based on the SQL injection flaw I described above. "Simply" craft an incorrect query with the XSS code in order to achieve that the admin (who views the visitor's details in the backend) gets an SQL error. The incorrect query gets displayed, e. g. SELECT wert, titel FROM `chc_pages` WHERE ( wert =[incorrect query with XSS] AND homepage_id = 1) ORDER BY monat DESC; Error number: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near [...] The XSS code should get executed right away since it is part of the "incorrect query", stealing the admin's cookies, redirecting him to another website or implementing malicious external documents is possible.