tagline: Confidence in the Connected World
CIS Logo
HomeResourcesAdvisoriesMultiple Vulnerabilities in Drupal Could Allow for Remote Code Execution

Multiple Vulnerabilities in Drupal Could Allow for Remote Code Execution

MS-ISAC ADVISORY NUMBER:

2017-059

DATE(S) ISSUED:

06/22/2017

OVERVIEW:

Multiple vulnerabilities have been discovered in Drupal core module, the most severe of which could allow for remote code execution. Drupal is an open source content management system (CMS) written in PHP. Successful exploitation of the most severe of these vulnerabilities could allow for remote code execution. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

THREAT INTELLIGENCE:

According to Drupal, there have been reports that CVE-2017- 6922 is being exploited in the wild for spam purposes.

SYSTEMS AFFECTED:

  • Drupal Core versions prior to 8.3.4 and 7.5.6

RISK:

Government:
  • Large and medium government entities: HIGH
  • Small government entities: MEDIUM
Businesses:
  • Large and medium business entities: HIGH
  • Small business entities: MEDIUM
Home Users:
LOW

TECHNICAL SUMMARY:

Multiple vulnerabilities have been discovered in Drupal core modules, the most severe of which could result in remote code execution. Details of the vulnerabilities are as follows:

  • A remote code execution vulnerability exists because PECL YAML parser does not handle PHP objects safely during certain operations within Drupal core. (CVE-2017- 6920)
  • An access vulnerability exists because the file REST resource does not properly validate some fields when manipulating files. (CVE-2017- 6921)
  • An access vulnerability exists because files uploaded by anonymous users into a private file system can be accessed by other anonymous users. (CVE-2017- 6922)

Successful exploitation of the most severe of these vulnerabilities could allow for remote code execution. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

RECOMENDATIONS:

We recommend the following actions be taken:

  • Apply appropriate patches provided by Drupal to vulnerable systems immediately after appropriate testing.
  • Ensure no unauthorized system changes have occurred before applying patches.
  • Run all software as a non-privileged user to diminish effects of a successful attack.
  • Apply the Principle of Least Privilege to all systems and services.

REFERENCES:

Get Email Updates When Cyber Threats Like This Arise

Arrow Subscribe to Advisories

Protect Your Systems from Cyber Threats Like This

CIS Controls That Help Avoid This Issue Arrow CIS Control 4: Continuous Vulnerability Assessment and Remediation Arrow CIS Control 18: Application Software Security

Information Hub: Advisories



Pencil Benchmark 17 Aug 2017

Pencil Blog post 14 Aug 2017

Pencil Blog post 11 Aug 2017