CVE-2022-31103 : Security Advisory and Response

A deep dive into the denial of service vulnerability in lettersanitizer below version 1.0.2 that impacts the in-browser email renderer.

Understanding CVE-2022-31103

lettersanitizer is a DOM-based HTML email sanitizer used for in-browser email rendering. The vulnerability arises in versions below 1.0.2 due to improper handling of CSS at-rules.

What is CVE-2022-31103?

All versions of lettersanitizer prior to 1.0.2 are susceptible to a denial of service issue triggered when processing a CSS at-rule

@keyframes

. This vulnerability poses a high availability impact.

The Impact of CVE-2022-31103

The vulnerability exposes users to potential denial of service attacks, particularly affecting those utilizing react-letter, which depends on lettersanitizer. It has a CVSS base score of 7.5, categorizing it as high severity.

Technical Details of CVE-2022-31103

The vulnerability stems from an improper check for unusual or exceptional conditions (CWE-754), leading to a susceptiblity in rendering CSS at-rules.

Vulnerability Description

The issue allows threat actors to exploit the CSS

@keyframes

at-rule, impacting systems using lettersanitizer below version 1.0.2.

Affected Systems and Versions

lettersanitizer versions earlier than 1.0.2 are impacted by this vulnerability, potentially affecting in-browser email rendering processes.

Exploitation Mechanism

Attackers can exploit this issue by crafting malicious CSS

@keyframes

at-rules, causing a denial of service condition in systems running the vulnerable versions.

Mitigation and Prevention

Understanding the steps to mitigate the risk and prevent exploitation of CVE-2022-31103.

Immediate Steps to Take

Users are advised to update lettersanitizer to version 1.0.2 or newer to patch the vulnerability and prevent potential denial of service attacks.

Long-Term Security Practices

Practicing secure coding, regularly updating dependencies, and staying informed about security advisories are crucial for maintaining a secure development environment.

Patching and Updates

Stay vigilant for security updates and patches released by mat-sz to address vulnerabilities and enhance the security posture of your applications.