Pallets Jinja str.format Sandbox Escape Vulnerability [CVE-2016-10745]

CVE Number – CVE-2016-10745

A vulnerability in Pallets Jinja could allow an unauthenticated, remote attacker to bypass security restrictions on a targeted system.

The vulnerability is due to the way string formatting works in Python, which could allow the str.formatmethod to be used to escape the sandbox on a targeted system. An attacker could exploit this vulnerability by sending a request that submits malicious input to the targeted system. A successful exploit could allow the attacker to bypass security restrictions and escape the sandbox environment, and then conduct further attacks.Pallets has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, the attacker must send a request that submits malicious input to the targeted system, making exploitation more difficult in environments that restrict network access from untrusted sources.

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

• Pallets has released a blog post at the following link: Jinja 2.8.1 Security Release

Fixed Software

• Pallets has released software updates at the following link: Jinja 2.8.1