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Drupal Security Updates Patch Five Vulnerabilities

The developers of Drupal, the open source content management system (CMS) currently used by more than 1.1 million websites, have address several security issues with the release of versions 7.39 and 6.37.

The security advisory published on Wednesday by Drupal reveals that version 7 is affected by a cross-site scripting (XSS) vulnerability that can be exploited to launch attacks by invoking Drupal.ajax() on a whitelisted HTML element.

The flaw does not affect Drupal 6 and it cannot be exploited on websites that prevent untrusted users from entering HTML. The issue has been addressed by getting the Ajax system to validate URLs before an Ajax request is made.

A different XSS vulnerability, affecting both Drupal 6 and 7, exists in the autocomplete functionality of forms because the requested URL is not sanitized properly. This security hole can only be exploited by a malicious user that is allowed to upload files.

“For security reasons, the autocomplete system now makes Ajax requests to non-clean URLs only, although protection is also in place for custom code that does so using clean URLs,” Drupal explained.

Drupal developers warn that version 7 of the CMS is plagued by a SQL injection vulnerability that allows an attacker with elevated privileges to inject malicious code in SQL comments. The flaw, found in the SQL comment filtering system, can only be exploited on one contributed module.

Drupal 7.39 and 6.37 also address a cross-site request forgery (CSRF) vulnerability affecting the form API. The weakness allows a malicious user to upload files to vulnerable websites under another user’s account. Developers have pointed out that files uploaded by attackers are only temporary, which means that they are deleted automatically after 6 hours.

“When form API token validation fails (for example, when a cross-site request forgery attempt is detected, or a user tries to submit a form after having logged out and back in again in the meantime), the form API now skips calling form element value callbacks, except for a select list of callbacks provided by Drupal core that are known to be safe. In rare cases, this could lead to data loss when a user submits a form and receives a token validation error, but the overall effect is expected to be minor,” Drupal said in the release notes.

The last vulnerability patched in Drupal 6 and 7 is an information disclosure issue related to menu links.

“Users without the ‘access content’ permission can see the titles of nodes that they do not have access to, if the nodes are added to a menu on the site that the users have access to,” reads Drupal’s advisory.

The vulnerabilities affect Drupal core 6.x versions prior to 6.37 and Drupal core 7.x versions prior to 7.39. CVE identifiers have yet to be assigned to these vulnerabilities.

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Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.