Date: 
Tuesday, Nov 15th, 2016
Advisory ID: 
BACKDROP-SA-CORE-2016-003
Vulnerabilities: 
  • Open Redirect
  • Denial of Service
  • Multiple vulnerabilities
Versions affected: 
  • Backdrop Core 1.5.x versions prior to 1.5.2
Description: 

Inconsistent name for term access query

Backdrop provides a mechanism to alter database SELECT queries before they are executed. Contributed and custom modules may use this mechanism to restrict access to certain entities by implementing hook_query_alter() or hook_query_TAG_alter() in order to add additional conditions. Queries can be distinguished by means of query tags. As the documentation on EntityFieldQuery::addTag() suggests, access-tags on entity queries normally follow the form ENTITY_TYPE_access (e.g. node_access). However, the taxonomy module's access query tag predated this system and used term_access as the query tag instead of taxonomy_term_access.

As a result, before this security release modules wishing to restrict access to taxonomy terms may have implemented an unsupported tag, or needed to look for both tags (term_access and taxonomy_term_access) in order to be compatible with queries generated both by Backdrop core as well as those generated by contributed modules like Reference. Otherwise information on taxonomy terms might be disclosed to unprivileged users.

Cancel links on entity and confirmation forms allow external URLs to be injected

Under some conditions this would allow the cancel links in some forms to redirect to an external site.

Denial of service via transliterate mechanism

A specially crafted URL can cause a denial of service via the transliterate mechanism.

Solution: 

Upgrade your site to the latest version of Backdrop CMS. Download available at Backdrop CMS 1.5.2 release page. Update instructions are available at https://backdropcms.org/upgrade#from-previous-versions.

Reported By: 

Inconsistent name for term access query

Cancel links on entity and confirmation forms allow external URLs to be injected
Denial of service via transliterate mechanism
Fixed By: 
Inconsistent name for term access query
Cancel links on entity and confirmation forms allow external URLs to be injected
Denial of service via transliterate mechanism
Coordinated By: 
  • Nate Haug of the Backdrop CMS Security Team

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