CVE-2020-26216 Explained : Impact and Mitigation

TYPO3 Fluid before versions 2.0.8, 2.1.7, 2.2.4, 2.3.7, 2.4.4, 2.5.11, and 2.6.10 is vulnerable to Cross-Site Scripting (XSS) attacks. This vulnerability allows malicious actors to execute scripts in a victim's web browser, potentially leading to unauthorized actions.

Understanding CVE-2020-26216

TYPO3 Fluid, a popular templating engine, is susceptible to multiple XSS vulnerabilities that could be exploited by attackers to inject and execute malicious scripts on the target system.

What is CVE-2020-26216?

TYPO3 Fluid versions prior to 2.0.8, 2.1.7, 2.2.4, 2.3.7, 2.4.4, 2.5.11, and 2.6.10 are affected by Cross-Site Scripting (XSS) vulnerabilities. These vulnerabilities allow attackers to inject and execute malicious scripts in the context of a user's browser, potentially compromising sensitive data or performing unauthorized actions.

The Impact of CVE-2020-26216

The impact of this vulnerability is rated as HIGH according to the CVSS v3.1 base score of 8.0. The following impacts are identified:

Attack Complexity: High
Attack Vector: Network
Confidentiality Impact: High
Integrity Impact: High
Privileges Required: None
User Interaction: Required
Scope: Changed
Availability Impact: None

Technical Details of CVE-2020-26216

TYPO3 Fluid's vulnerability details and affected systems are outlined below:

Vulnerability Description

Three XSS vulnerabilities have been identified in TYPO3 Fluid:

TagBasedViewHelper allowed XSS through maliciously crafted additionalAttributes arrays.
ViewHelpers using certain traits could receive content arguments in an unescaped format.
Subclasses of AbstractConditionViewHelper could receive arguments in an unescaped format.

Affected Systems and Versions

The following versions of TYPO3 Fluid are affected:

= 2.0.0, < 2.0.8

= 2.1.0, < 2.1.7

= 2.2.0, < 2.2.4

= 2.3.0, < 2.3.7

= 2.4.0, < 2.4.4

= 2.5.0, < 2.5.11

= 2.6.0, < 2.6.10

Exploitation Mechanism

Attackers can exploit these vulnerabilities by injecting malicious scripts into the affected TYPO3 Fluid versions, which are then executed in the context of a user's browser, leading to potential data theft or unauthorized actions.

Mitigation and Prevention

To address CVE-2020-26216 and protect systems from potential exploitation, the following steps are recommended:

Immediate Steps to Take

Update TYPO3 Fluid to versions 2.0.8, 2.1.7, 2.2.4, 2.3.7, 2.4.4, 2.5.11, or 2.6.10 that contain fixes for the identified vulnerabilities.

Long-Term Security Practices

Regularly monitor and apply security patches and updates to TYPO3 Fluid and other software components to mitigate future vulnerabilities.

Patching and Updates

Stay informed about security advisories and updates from TYPO3 to promptly address any new vulnerabilities and ensure the security of your systems.