CVE-2016-10105 (published 2017-01-03T06:59Z)

admin/plugin.php in Piwigo through 2.8.3 doesn't validate the sections variable while using it to include files. This can cause information disclosure and code execution if it contains a .. sequence.

Severity: HIGH
CVSS v2 base score: 7.5 (AV:N/AC:L/Au:N/C:P/I:P/A:P)
CVSS v3 base score: 9.8, CRITICAL (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-200
cwe_name: Exposure of Sensitive Information to an Unauthorized Actor
description: The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
extended_description: 
	   There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker.  Some kinds of sensitive information include:
       
         private, personal information, such as personal messages, financial data, health records, geographic location, or contact details
         system status and environment, such as the operating system and installed packages
		 business secrets and intellectual property
		 network status and configuration
		 the product's own code or internal state
         metadata, e.g. logging of connections or message headers
		 indirect information, such as a discrepancy between two internal operations that can be observed by an outsider
       
	    Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected.  These parties include:
               
                  the product's own users
                  people or organizations whose information is created or used by the product, even if they are not direct product users
		  the product's administrators, including the admins of the system(s) and/or networks on which the product operates
                  the developer
               
	    Information exposures can occur in different ways:
               
                  the code explicitly inserts sensitive information into resources or messages that are intentionally made accessible to unauthorized actors, but should not contain the information - i.e., the information should have been "scrubbed" or "sanitized"
                  a different weakness or mistake indirectly inserts the sensitive information into resources, such as a web script error revealing the full system path of the program.
                  the code manages resources that intentionally contain sensitive information, but the resources are unintentionally made accessible to unauthorized actors. In this case, the information exposure is resultant - i.e., a different weakness enabled the access to the information in the first place.
               
	    It is common practice to describe any loss of confidentiality as an "information exposure," but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read.  CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.
         
         
cwe_id: CWE-284
cwe_name: Improper Access Control
description: The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
extended_description: 
            Access control involves the use of several protection mechanisms such as:
            
               Authentication (proving the identity of an actor)
               Authorization (ensuring that a given actor can access a resource), and
               Accountability (tracking of activities that were performed)
            
            When any mechanism is not applied or otherwise fails, attackers can compromise the security of the product by gaining privileges, reading sensitive information, executing commands, evading detection, etc.
            There are two distinct behaviors that can introduce access control weaknesses:
               
                  Specification: incorrect privileges, permissions, ownership, etc. are explicitly specified for either the user or the resource (for example, setting a password file to be world-writable, or giving administrator capabilities to a guest user). This action could be performed by the program or the administrator.
                  Enforcement: the mechanism contains errors that prevent it from properly enforcing the specified access control requirements (e.g., allowing the user to specify their own privileges, or allowing a syntactically-incorrect ACL to produce insecure settings). This problem occurs within the program itself, in that it does not actually enforce the intended security policy that the administrator specifies.
               
         
		 

Fix information:
repo_url: https://github.com/Piwigo/Piwigo
commit_details: repo_url: https://github.com/Piwigo/Piwigo
author: plegall
author_date: 2017-01-01 19:40:53+01:00
msg: fixes #574, new checks on plugin section in URL
repository: repo_url: https://github.com/Piwigo/Piwigo
repo_name: Piwigo/Piwigo
description: Manage your photos with Piwigo, a full featured open source photo gallery application for the web. Star us on Github! More than 200 plugins and themes available. Join us and contribute!
repo_language: PHP
owner: Piwigo
file_changes: filename: plugin.php
change_type: ModificationType.MODIFY
diff: @@ -32,10 +32,16 @@ check_status(ACCESS_ADMINISTRATOR);
 $sections = explode('/', $_GET['section'] );
 for ($i=0; $i<count($sections); $i++)
 {
-  if (empty($sections[$i]) or $sections[$i]=='..')
+  if (empty($sections[$i]))
   {
     unset($sections[$i]);
     $i--;
+    continue;
+  }
+
+  if ($sections[$i] == '..' or !preg_match('/^[a-zA-Z_\.-]+$/', $sections[$i]))
+  {
+    die('invalid section token ['.htmlentities($sections[$i]).']');
   }
 }
 

programming_language: PHP