Yara Object Lookup Functionality Denial of Service Vulnerability [CVE-2019-5020]

CVE number – CVE-2019-5020

A vulnerability in the object lookup functionality of Yara could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted system. The vulnerability exists because the affected software reads a negative value to satisfy an assert. An attacker could exploit this vulnerability by sending a crafted binary file to the targeted system.

A successful could allow the attacker to cause a DoS condition on the targeted system. Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available. VirusTotal has confirmed this vulnerability and released software updates.


  • To exploit this vulnerability, the attacker must have network access and the ability to send a crafted binary file to the targeted system. These requirements could reduce the likelihood of a successful attack.


  • 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

  • VirusTotal has released a security issue at the following link: #1023

Fixed Software

  • VirusTotal has released software updates at the following link: v3.10.0

Duncan Newell

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.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: