Description Contao >=4.0.0 allows backend XSS via HTML attributes to an HTML field. Fixed in 4.4.56, 4.9.18, 4.11.7. Remediation References CVE-2021-35955 Related Vulnerabilities Oracle Application Server Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') Vulnerability (CVE-2006-0586) Apache HTTP Server CVE-2016-8743 Vulnerability (CVE-2016-8743) WordPress Plugin Enable Media Replace Arbitrary File Upload (4.0.1) PostgreSQL Numeric Errors Vulnerability (CVE-2010-4015) WordPress Plugin Welcart e-Commerce Multiple Vulnerabilities (1.3.12) Severity Medium Classification CVE-2021-35955 CWE-707 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N Tags Missing Update Known Vulnerabilities