SB2021041354 - Multiple vulnerabilities in Joomla!

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Cross-site scripting (CVE-ID: CVE-2021-26030)

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data passed via the logo parameter of the default templates on error pages. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

2) PHP file inclusion (CVE-ID: CVE-2021-26031)

The vulnerability allows a remote user to include and execute arbitrary PHP files on the server.

The vulnerability exists due to incorrect input validation when including PHP files on module layout settings. A remote user can send a specially crafted HTTP request to the affected application, include and execute arbitrary PHP code on the system with privileges of the web server.

Remediation

Install update from vendor's website.

References

• https://developer.joomla.org/security-centre/850-20210401-core-escape-xss-in-logo-parameter-error-pages.html
• https://developer.joomla.org/security-centre/851-20210402-core-inadequate-filters-on-module-layout-settings.html