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 Ruby on Rails Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') Vulnerability (CVE-2017-17917) Jenkins Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') Vulnerability (CVE-2017-1000392) WordPress Plugin Downloads Manager 'upload.php' Arbitrary File Upload (0.2) Joomla Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') Vulnerability (CVE-2022-27913) Moodle Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') Vulnerability (CVE-2012-2363) 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 CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N Tags Missing Update Known Vulnerabilities