CVE-2020-1888 : Security Advisory and Response

A vulnerability in HHVM versions allows for potential denial-of-service attacks due to insufficient boundary checks when decoding JSON.

Understanding CVE-2020-1888

This CVE concerns HHVM, a virtual machine and just-in-time compiler for PHP.

What is CVE-2020-1888?

The vulnerability involves HHVM versions with inadequate boundary checks when decoding JSON, potentially leading to denial-of-service.

The Impact of CVE-2020-1888

The vulnerability could allow an attacker to trigger a denial-of-service condition on systems using affected versions of HHVM.

Technical Details of CVE-2020-1888

This section delves into the specifics of the vulnerability in HHVM.

Vulnerability Description

The issue arises from insufficient bounds checking in handling JSON decoding, potentially resulting in out-of-bounds memory access and DOS attacks.

Affected Systems and Versions

Versions affected: 4.45.0, 4.44.0, 4.43.0, 4.42.0, 4.41.0, 4.40.0, 4.39.0, 4.33.0 - 4.38.0, 4.9.0 - 4.32.0, and versions earlier than 4.8.7.

Exploitation Mechanism

The vulnerability can be exploited by an attacker sending specially crafted JSON data to trigger the out-of-bounds memory read.

Mitigation and Prevention

Steps to secure systems against CVE-2020-1888.

Immediate Steps to Take

Apply security patches provided by HHVM promptly.
Update HHVM to a version that addresses the vulnerability.
Implement network defenses to detect and block malicious JSON payloads.

Long-Term Security Practices

Regularly update HHVM and other software components to maintain security.
Conduct security audits to identify and address potential vulnerabilities in the environment.

Patching and Updates

Stay informed about security advisories from HHVM and promptly apply patches to mitigate risks.