CVE-2021-21235 : What You Need to Know

An infinite loop vulnerability has been identified in kamadak-exif, a pure Rust exif parsing library. This vulnerability exists in version 0.5.2, allowing crafted PNG files to trigger an infinite loop in the parsing mechanism. The issue is resolved in version 0.5.3, with no available workarounds. Only applications passing files with the PNG signature to Reader::read_from_container are impacted.

Understanding CVE-2021-20657

This section provides an overview of the CVE-2021-21235 vulnerability.

What is CVE-2021-20657?

The CVE-2021-21235 vulnerability affects the exif parsing library, kamadak-exif, in version 0.5.2. It allows crafted PNG files to trigger an infinite loop when processed through reader::read_from_container.

The Impact of CVE-2021-20657

The impact of CVE-2021-21235 is rated as MEDIUM. Attackers exploiting this vulnerability can cause denial of service by triggering an infinite loop in the parsing mechanism.

Technical Details of CVE-2021-20657

This section dives into the technical aspects of the CVE-2021-21235 vulnerability.

Vulnerability Description

In version 0.5.2 of kamadak-exif, an infinite loop can be triggered when processing crafted PNG files through reader::read_from_container.

Affected Systems and Versions

The vulnerability affects kamadak-exif version 0.5.2. Applications passing PNG files to Reader::read_from_container are vulnerable.

Exploitation Mechanism

Attackers can exploit this vulnerability by providing crafted PNG files to the reader::read_from_container function, causing an infinite loop.

Mitigation and Prevention

This section outlines the steps to mitigate and prevent the CVE-2021-20657 vulnerability.

Immediate Steps to Take

Users are advised to update kamadak-exif to version 0.5.3 to remediate the infinite loop issue triggered by crafted PNG files.

Long-Term Security Practices

Implement secure coding practices, conduct regular security audits, and stay informed about updates to prevent similar vulnerabilities in the future.

Patching and Updates

Ensure timely installation of patches and updates released by the vendor to address security vulnerabilities and protect systems from exploitation.