CVE-2021-29444 : Exploit Details and Defense Strategies

This article provides an in-depth analysis of CVE-2021-29444, highlighting the vulnerability in jose-browser-runtime and its impact on cryptographic functions.

Understanding CVE-2021-29444

CVE-2021-29444 involves a padding oracle attack due to an observable timing discrepancy in jose-browser-runtime, a cryptographic package.

What is CVE-2021-29444?

jose-browser-runtime, in versions prior to 3.11.4, exhibited a timing discrepancy during AES_CBC_HMAC_SHA2 Algorithm decryption, leading to a padding oracle vulnerability.

The Impact of CVE-2021-29444

The vulnerability allowed an adversary to exploit the padding oracle to decrypt data without the decryption key, posing a threat to confidentiality.

Technical Details of CVE-2021-29444

The vulnerability description, affected systems and versions, and exploitation mechanism are as follows:

Vulnerability Description

In versions below 3.11.4, the timing difference in padding errors exposed a padding oracle vulnerability.

Affected Systems and Versions

jose-browser-runtime versions earlier than 3.11.4 are impacted by this vulnerability.

Exploitation Mechanism

Attackers could utilize the observable timing discrepancy to execute a padding oracle attack and decrypt data.

Mitigation and Prevention

Understanding the steps to mitigate the risk and prevent such vulnerabilities is crucial:

Immediate Steps to Take

Users are advised to upgrade to jose-browser-runtime version ^3.11.4 to patch the vulnerability.

Long-Term Security Practices

Implement secure coding practices and regularly update cryptographic libraries to prevent similar vulnerabilities.

Patching and Updates

Stay informed about security advisories and promptly apply patches to secure your systems and data.