Impact

Users can upload SVG files with malicious code, which is then executed in the back end and/or front end.

Patches

Update to Contao 4.13.54, 5.3.30 or 5.5.6.

Workarounds

Remove svg,svgz from the allowed upload file types in the system settings and from contao.editablefiles in the config.yaml.

References

https://contao.org/en/security-advisories/cross-site-scripting-through-svg-uploads

For more information

If you have any questions or comments about this advisory, open an issue in contao/contao.

Impact

It is possible for untrusted users to load arbitrary PHP files via insert tags.

Installations are only affected if there are untrusted back end users.

Patches

Update to Contao 4.4.56, 4.9.18 or 4.11.7.

Workarounds

Disable the login for untrusted back end users.

References

https://contao.org/en/security-advisories/php-file-inclusion-via-insert-tags

For more information

If you have any questions or comments about this advisory, open an issue in contao/contao.

Impact

It is possible for untrusted users to gain administrator rights with the form generator.

Installations are only affected if there are untrusted back end users with access to the form generator.

Patches

Update to Contao 4.4.56, 4.9.18 or 4.11.7.

Workarounds

Disable the form generator or disable the login for untrusted back end users.

References

https://contao.org/en/security-advisories/privilege-escalation-with-the-form-generator

For more information

If you have any questions or comments about this advisory, open an issue in contao/contao.