CVE-2019-15608 : Security Advisory and Response

Yarn package manager versions prior to 1.19.0 are susceptible to a TOCTOU vulnerability affecting package integrity validation.

Understanding CVE-2019-15608

This CVE involves a security flaw in yarn versions before 1.19.0 that could lead to cache pollution attacks.

What is CVE-2019-15608?

The vulnerability in yarn versions < 1.19.0 arises from an issue where the hash calculation is done before storing a package in the cache but not recalculated when retrieving the package, potentially enabling cache pollution attacks.

The Impact of CVE-2019-15608

The TOCTOU vulnerability in yarn versions prior to 1.19.0 could allow malicious actors to manipulate the package cache, leading to security breaches and unauthorized access.

Technical Details of CVE-2019-15608

Yarn package manager versions before 1.19.0 are affected by this vulnerability.

Vulnerability Description

The vulnerability stems from the hash calculation process in yarn, which opens the door to cache pollution attacks.

Affected Systems and Versions

Product: Yarn
Vendor: N/A
Versions Affected: < 1.19.0

Exploitation Mechanism

The vulnerability occurs due to the hash calculation process not being updated when retrieving packages from the cache, potentially allowing for cache pollution attacks.

Mitigation and Prevention

Steps to address and prevent the CVE-2019-15608 vulnerability.

Immediate Steps to Take

Upgrade yarn to version 1.19.0 or newer to mitigate the vulnerability.
Monitor for any unusual package cache activities.

Long-Term Security Practices

Regularly update yarn and other software dependencies to the latest versions.
Implement secure coding practices to prevent similar vulnerabilities.

Patching and Updates

Stay informed about security updates and patches released by yarn to address vulnerabilities like CVE-2019-15608.