Drupal PHP built-in phar Stream Wrapper Remote Code Execution Vulnerability [CVE-2019-6339]
CVE Number – CVE-2019-6339
A vulnerability in the PHP built-in phar stream wrapper used in Drupal could allow an authenticated, remote attacker to execute arbitrary code on a targeted system.
The vulnerability is due to insufficient validation of user-supplied input by the affected software when file operations are performed on an untrusted phar:// URI. An attacker could exploit this vulnerability by submitting malicious input to the targeted system when performing a file operation. A successful exploit could allow the attacker to execute arbitrary code.
Drupal has confirmed the vulnerability and released software updates.
Analysis
- To exploit this vulnerability, the attacker must have the privileges to perform administrative actions on the targeted system. This access requirement could reduce the likelihood of a successful exploit.
Although this vulnerability has a medium SIR rating due to the access complexity and the need for administrative access for an exploit to occur, an exploit could allow the attacker to execute arbitrary code. As a result, the vendor rated this vulnerability as a critical security risk.
Safeguards
- Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
Administrators are advised to monitor affected systems.
Vendor Announcements
- Drupal.org has released a security advisory at the following link: SA-CORE-2019-002
Fixed Software
- Drupal.org has released software updates at the following links:
Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.