Zero-day vulnerability in Drupal

Security restrictions bypass
CVE-2017-6922

There are confirmed reports indicating that this vulnerability has been publicly exploited in spam campaigns. The attackers were creating accounts, uploading files with spam links to advertise or influence SEO rankings.

Vulnerability details

Advisory: SB2017062301 - Multiple vulnerabilities in Drupal

Vulnerable component: Drupal

CVE-ID: CVE-2017-6922

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:H/RL:O/RC:C

CWE-ID: CWE-693 - Protection Mechanism Failure

Description:

The vulnerability allows a remote attacker to bypass security restrictions on the target system.

The weakness exists due to insufficient file protection. A remote attacker can bypass access restrictions and view private files that have been uploaded by an anonymous user but not permanently attached to content on the site.

Successful exploitation of the vulnerability may result in access bypass.

Note: The vulnerability was being actively exploited for spam purposes.

External links:

http://securityaffairs.co/wordpress/60335/hacking/drupal-cve-2017-6922.html
https://www.drupal.org/SA-CORE-2017-003

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.