CVE-2020-1916 Explained : Impact and Mitigation

An incorrect size calculation in ldap_escape may lead to an integer overflow when overly long input is passed in, resulting in an out-of-bounds write. This issue affects HHVM prior to 4.56.2, all versions between 4.57.0 and 4.78.0, 4.79.0, 4.80.0, 4.81.0, 4.82.0, 4.83.0.

Understanding CVE-2020-1916

Heap-based Buffer Overflow vulnerability in HHVM.

What is CVE-2020-1916?

This CVE highlights a vulnerability in HHVM that could lead to an out-of-bounds write due to an incorrect size calculation in the ldap_escape function.

The Impact of CVE-2020-1916

Attackers can exploit this vulnerability to trigger an integer overflow by providing excessively long input, potentially leading to a security breach.

Technical Details of CVE-2020-1916

Heap-based Buffer Overflow vulnerability in HHVM.

Vulnerability Description

The issue arises from an incorrect size calculation in ldap_escape, potentially resulting in an integer overflow and an out-of-bounds write.

Affected Systems and Versions

HHVM versions prior to 4.56.2
All versions between 4.57.0 and 4.78.0
4.79.0, 4.80.0, 4.81.0, 4.82.0, 4.83.0

Exploitation Mechanism

An attacker needs to provide overly long input to the ldap_escape function, triggering the integer overflow and subsequent out-of-bounds write.

Mitigation and Prevention

Implement the following measures to safeguard your systems against CVE-2020-1916:

Immediate Steps to Take

Apply patches provided by HHVM to fix the vulnerability.
Monitor system logs for any suspicious activities that might indicate exploitation.

Long-Term Security Practices

Regularly update HHVM to ensure you have the latest security enhancements.
Employ network security solutions to detect and prevent potential threats.

Patching and Updates

Stay informed about security updates released by HHVM and promptly apply them to address known vulnerabilities.