CVE-2021-21339 : Exploit Details and Defense Strategies

TYPO3.CMS, an open source PHP-based web content management system, is affected by a vulnerability where user session identifiers were stored in cleartext without additional cryptographic hashing. This can lead to a security risk when combined with other attacks such as SQL injection. The issue affects versions before 6.2.57, 7.6.51, 8.7.40, 9.5.25, 10.4.14, and 11.1.1 which have now been fixed.

Understanding CVE-2021-21339

This CVE pertains to the cleartext storage of session identifiers in TYPO3.CMS, potentially exposing user data to exploitation.

What is CVE-2021-21339?

CVE-2021-21339 refers to the vulnerability in TYPO3.CMS where session identifiers were stored in cleartext, posing a risk to user confidentiality.

The Impact of CVE-2021-21339

The impact of this CVE is classified as medium severity with a CVSS base score of 5.9. It can lead to high confidentiality impact and requires a high attack complexity to be exploited.

Technical Details of CVE-2021-21339

The vulnerability involves storing user session identifiers in cleartext without additional cryptographic hashing, making it susceptible to exploitation and data breaches.

Vulnerability Description

User session identifiers stored in cleartext can be exploited in combination with other attacks like SQL injection, posing a serious security risk.

Affected Systems and Versions

Versions of TYPO3.CMS affected include >= 6.2.0, <= 6.2.56, >= 7.0.0, <= 7.6.50, >= 8.0.0, <= 8.7.39, >= 9.0.0, <= 9.5.24, >= 10.0.0, <= 10.4.13, >= 11.0.0, <= 11.1.0.

Exploitation Mechanism

The vulnerability cannot be directly exploited but requires a chained attack, such as SQL injection in another system component, to compromise user session data.

Mitigation and Prevention

It is crucial to take immediate steps to address CVE-2021-21339 and implement long-term security practices to safeguard systems from similar vulnerabilities.

Immediate Steps to Take

Update TYPO3.CMS to the fixed versions 6.2.57, 7.6.51, 8.7.40, 9.5.25, 10.4.14, 11.1.1 to mitigate the risk of cleartext session identifier storage.

Long-Term Security Practices

Regularly monitor and update security configurations, conduct security audits, and educate users on best practices to enhance overall system security.

Patching and Updates

Stay informed about security advisories and promptly apply patches released by TYPO3 to address vulnerabilities and improve system security.