CVE-2018-6345 : What You Need to Know

A vulnerability has been identified in the function number_format in HHVM, potentially leading to a heap overflow issue when an excessively large value is provided as the second argument ($dec_points). This vulnerability affects all supported versions of HHVM.

Understanding CVE-2018-6345

This CVE involves a heap-based buffer overflow vulnerability in HHVM, specifically in the number_format function.

What is CVE-2018-6345?

The vulnerability in the number_format function of HHVM can trigger a heap overflow when an extremely large value is used as the second argument, potentially causing invalid string length generation and negative interactions with other functions.

The Impact of CVE-2018-6345

The vulnerability poses a security risk as it can lead to a heap overflow issue, potentially allowing attackers to execute arbitrary code or crash the application.

Technical Details of CVE-2018-6345

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability in HHVM's number_format function can result in a heap overflow due to the generation of a string with an invalid length.

Affected Systems and Versions

Product: HHVM
Vendor: Facebook
Affected Versions: 3.30.2, 3.30.0 (custom), 3.27.6, unspecified custom versions less than 3.27.6

Exploitation Mechanism

The vulnerability can be exploited by providing an excessively large value as the second argument ($dec_points) to the number_format function, triggering the heap overflow.

Mitigation and Prevention

To address CVE-2018-6345, follow these mitigation strategies:

Immediate Steps to Take

Apply the patches provided by Facebook for HHVM.
Monitor official sources for updates and security advisories.
Restrict access to vulnerable systems.

Long-Term Security Practices

Regularly update HHVM to the latest secure versions.
Conduct security audits and code reviews to identify and address vulnerabilities.
Implement secure coding practices to prevent buffer overflow vulnerabilities.

Patching and Updates

Facebook has released patches for HHVM to address the vulnerability.
Stay informed about security updates and apply patches promptly to secure systems.