Zstandard one-pass compression Functions Race Condition Vulnerability [CVE-2019-11922]

CVE number – CVE-2019-11922

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

The vulnerability is due to a race condition that could occur in the one-pass compression functions of the affected software. An attacker could exploit this vulnerability by sending a request that submits malicious input to the targeted system. A successful exploit could trigger an out-of-bounds write condition that the attacker could use to execute arbitrary code or cause a DoS condition. 

Facebook has confirmed the vulnerability and released software updates.

Analysis

• To exploit this vulnerability, an 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

• Facebook has released a git commit at the following link: commit 3e5cdf1b6a85843e991d7d10f6a2567c15580da0

Fixed Software

• Facebook has released software updates at the following link: Zstandard 1.3.8