CVE-2019-11929 : Exploit Details and Defense Strategies

A vulnerability in HHVM versions prior to 3.30.10 and between 4.0.0 to 4.23.0 could allow unauthorized access to memory, potentially leading to remote code execution.

Understanding CVE-2019-11929

This CVE identifies a critical security issue in HHVM that could result in memory access violations and remote code execution.

What is CVE-2019-11929?

The vulnerability arises from inadequate boundary checks during number formatting in HHVM, enabling unauthorized memory access beyond allocated bounds.

The Impact of CVE-2019-11929

Exploitation of this vulnerability could lead to unauthorized access to memory and potentially allow attackers to execute remote code on affected systems.

Technical Details of CVE-2019-11929

This section delves into the technical aspects of the CVE.

Vulnerability Description

The vulnerability stems from insufficient boundary checks during number formatting in HHVM, potentially enabling unauthorized memory access and remote code execution.

Affected Systems and Versions

HHVM versions prior to 3.30.10
HHVM versions between 4.0.0 and 4.8.5
HHVM versions between 4.9.0 and 4.18.2
HHVM versions 4.19.0, 4.19.1, 4.20.0, 4.20.1, 4.20.2, 4.21.0, 4.22.0, and 4.23.0

Exploitation Mechanism

The vulnerability allows attackers to manipulate number formatting in a way that grants unauthorized access to memory outside the allocated boundaries, potentially leading to remote code execution.

Mitigation and Prevention

Protecting systems from CVE-2019-11929 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply patches provided by HHVM promptly.
Monitor security advisories for updates on this vulnerability.
Implement network security measures to detect and block potential exploitation attempts.

Long-Term Security Practices

Regularly update HHVM to the latest secure versions.
Conduct security audits to identify and address vulnerabilities proactively.
Educate developers on secure coding practices to prevent similar issues in the future.

Patching and Updates

Facebook has released patches addressing the vulnerability. Ensure all affected HHVM instances are updated to the patched versions to mitigate the risk of exploitation.