CVE-2021-43561 Explained : Impact and Mitigation

An XSS issue was discovered in the google_for_jobs (aka Google for Jobs) extension before 1.5.1 and 2.x before 2.1.1 for TYPO3. The extension fails to properly encode user input for output in HTML context. A TYPO3 backend user account is required to exploit the vulnerability.

Understanding CVE-2021-43561

What is CVE-2021-43561?

CVE-2021-43561 refers to a cross-site scripting (XSS) vulnerability found in the google_for_jobs extension for TYPO3. The issue arises from inadequate encoding of user input, potentially allowing attackers to execute malicious scripts in the context of the affected web application.

The Impact of CVE-2021-43561

Exploitation of this vulnerability could lead to unauthorized actions being performed by attackers, compromising the integrity and confidentiality of data within the TYPO3 application. A TYPO3 backend user account is necessary for the successful exploitation of this issue.

Technical Details of CVE-2021-43561

Vulnerability Description

The XSS vulnerability in the google_for_jobs extension before version 1.5.1 and 2.x before 2.1.1 for TYPO3 arises from the lack of proper input validation and output encoding, allowing malicious scripts to be injected and executed in the context of the web application.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions affected: Before 1.5.1 and 2.x before 2.1.1

Exploitation Mechanism

To exploit this vulnerability, an attacker needs access to a TYPO3 backend user account. By submitting specially crafted input, the attacker can inject malicious scripts that get executed in the HTML context, potentially leading to unauthorized actions.

Mitigation and Prevention

Immediate Steps to Take

Update the google_for_jobs extension to the latest patched version to mitigate the vulnerability.
Restrict access to TYPO3 backend accounts and ensure strong authentication mechanisms.

Long-Term Security Practices

Implement input validation and output encoding mechanisms to prevent XSS attacks in web applications.
Regularly monitor and audit web application code for security vulnerabilities.

Patching and Updates

Apply security patches promptly and consistently to maintain the security of TYPO3 extensions and prevent exploitation of known vulnerabilities.