Facebook HHVM CVE-2019-11929 Memory Corruption Vulnerability

Description

Facebook HHVM is prone to a memory corruption vulnerability. An attacker can exploit this issue to execute arbitrary code in the context of the system. Failed exploit attempts will likely result in denial-of-service conditions.

Technologies Affected

• Facebook HHVM 3.14.2
• Facebook HHVM 3.14.3
• Facebook HHVM 3.30.3
• Facebook HHVM 3.30.9
• Facebook HHVM 4.18.2
• Facebook HHVM 4.19.0
• Facebook HHVM 4.19.1
• Facebook HHVM 4.20.0
• Facebook HHVM 4.20.1
• Facebook HHVM 4.20.2
• Facebook HHVM 4.21.0
• Facebook HHVM 4.22.0
• Facebook HHVM 4.23.0
• Facebook HHVM 4.9.0

Recommendations

Run all software as a nonprivileged user with minimal access rights.
To reduce the impact of latent vulnerabilities, run applications with the minimal amount of privileges required for functionality.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This includes but is not limited to requests that include NOP sleds and unexplained incoming and outgoing traffic. This may indicate exploit attempts or activity that results from a successful exploit.

Do not accept or execute files from untrusted or unknown sources.
To limit exposure to these and other latent vulnerabilities, never handle files that originate from unfamiliar or untrusted sources.

Do not follow links provided by unknown or untrusted sources.
To reduce the likelihood of successful exploits, never visit sites of questionable integrity or follow links provided by unfamiliar or untrusted sources.

Implement multiple redundant layers of security.
As an added precaution, deploy memory-protection schemes (such as nonexecutable stack/heap configuration and randomly mapped memory segments). This may complicate exploits of memory-corruption vulnerabilities.

Updates are available. Please see the references or vendor advisory for more information.