CVE-2021-21855 : What You Need to Know

Multiple exploitable integer overflow vulnerabilities exist within the MPEG-4 decoding functionality of the GPAC Project on Advanced Content library v1.0.1. A specially crafted MPEG-4 input can cause an integer overflow due to unchecked addition arithmetic resulting in a heap-based buffer overflow that causes memory corruption. An attacker can convince a user to open a video to trigger this vulnerability.

Understanding CVE-2021-21855

This section will delve into the details of the CVE-2021-21855 vulnerability, its impact, technical details, and mitigation strategies.

What is CVE-2021-21855?

CVE-2021-21855 involves multiple exploitable integer overflow vulnerabilities within the MPEG-4 decoding feature of the GPAC Project on Advanced Content library v1.0.1.

The Impact of CVE-2021-21855

The impact of CVE-2021-21855 is rated as high with a CVSS base score of 8.8. Attackers can exploit this vulnerability to trigger memory corruption via a specially crafted MPEG-4 input, leading to a heap-based buffer overflow.

Technical Details of CVE-2021-21855

Let's explore the technical aspects of this vulnerability in more detail.

Vulnerability Description

The vulnerability arises from unchecked addition arithmetic during MPEG-4 decoding, causing an integer overflow that leads to memory corruption and a heap-based buffer overflow.

Affected Systems and Versions

Systems running GPAC Project Advanced Content library v1.0.1 are affected by this CVE.

Exploitation Mechanism

An attacker can exploit this vulnerability by convincing a user to open a specially crafted video file, triggering the integer overflow and subsequent memory corruption.

Mitigation and Prevention

To mitigate the risks posed by CVE-2021-21855, consider the following strategies.

Immediate Steps to Take

Users should exercise caution when opening video files from untrusted sources to prevent exploitation of this vulnerability. Implementing network-level defenses can also help prevent remote attacks.

Long-Term Security Practices

Regularly update software and apply patches provided by the vendor to address known vulnerabilities and improve system security.

Patching and Updates

Ensure that you regularly check for updates from GPAC Project to address this specific CVE and other security issues.