Poppler Object::dictLookup Denial of Service Vulnerability [CVE-2018-20650]

CVE Number – CVE-2018-20650

A vulnerability in Poppler could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system.

The vulnerability is in the FileSpec class defined in the FileSpec.cc source code file of the affected software and exists because the affected software fails to properly perform a check for the dict data type when handling user-supplied input. An attacker could exploit this vulnerability by persuading a user to use the affected software to access a file that submits malicious input to the system. A successful exploit could result in a reachable Object::dictLookup assertion and cause the affected software to terminate abnormally. 

Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available. 

Poppler has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, the attacker may use misleading language or instructions to persuade a user to access a file that submits malicious input to the targeted system.

Safeguards

• Administrators are advised to apply the appropriate updates.
  
  Administrators are advised to allow only trusted users to have network access.
  
  Users are advised not to open email messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in email messages are safe, they are advised not to open them.
  
  Users are advised not to visit websites or follow links that have suspicious characteristics or cannot be verified as safe.
  
  Administrators are advised to use an unprivileged account when browsing the Internet.
  
  Administrators are advised to monitor critical systems.

Vendor Announcements

• Poppler has released an issue report at the following link: Issue #704

Fixed Software

• Poppler has released software updates at the following link: commit de0c0b8324e776f0b851485e0fc9622fc35695b7