Confirming an opt-in token does not invalidate previous opt-in tokens

Contao 3.0.0 to 3.5.30 and 4.0.0 to 4.4.7 contains an SQL injection vulnerability in the back end as well as in the listing module.

Contao before 3.5.39 and 4.x before 4.7.3 has a Weak Password Recovery Mechanism for a Forgotten Password.

Contao 4.x allows SQL Injection. Fixed in Contao 4.4.39 and Contao 4.7.5.

Contao CMS through 3.2.4 has PHP Object Injection Vulnerabilities

Contao Managed Edition v1.5.0 was discovered to contain a remote command execution (RCE) vulnerability via the component phpcli parameter.

An unauthenticated front end visitor can post a comment containing a XSS injection. The victim is any back end user who opens the Comments module, and moderation makes exposure certain rather than preventing it. No Content-Security-Policy header is sent on the Contao back end, so nothing mitigates the inline handler.

Impact

Anyone on the internet can inject script that executes in the Contao back end origin, under the session of whichever user opens the Comments module, with no click and no hover. From there the payload acts as that user through the back end: reading any module they can reach, creating a new administrator, or editing a template, which on Contao is a documented path from back end write access to code execution. Moderation does not help and in fact guarantees exposure, since unpublished comments are still inserted and a moderator has to open the list to act on them.

Impact

Back end users with access to the file manager can upload malicious files and execute them on the server.

Patches

Update to Contao 4.13.49, 5.3.15 or 5.4.3.

Workarounds

Configure your web server so it does not execute PHP files and other scripts in the Contao file upload directory.

References

https://contao.org/en/security-advisories/remote-command-execution-through-file-uploads

For more information

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

Credits

Thanks to Jakob Steeg from usd AG for reporting this vulnerability.

Impact

A back end user with access to the form generator can upload arbitrary files and execute them on the server.

Patches

Update to Contao 4.4.46 or 4.8.6.

Workarounds

Configure your web server so it does not execute PHP files and other scripts in the Contao file upload directory.

References

https://contao.org/en/security-advisories/unrestricted-file-uploads

For more information

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

A logged in back end user can include arbitrary existing PHP files by manipulating an URL parameter

Contao 4.7 allows CSRF.

Contao core prior to 2.11.4 has a SQL injection vulnerability in contao-2.11.3\system\modules\backend\Ajax.php

Impact

If the crawler is set to crawl protected pages, it sends the cookie header to externals URLs.

Patches

Update to Contao 4.13.40 or 5.3.4.

Workarounds

Disable crawling protected pages.

References

https://contao.org/en/security-advisories/session-cookie-disclosure-in-the-crawler

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.

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

Untrusted users can inject malicious code into the canonical tag, which is then executed on the web page (front end).

Patches

Update to Contao 4.13.3.

Workarounds

Disable canonical tags in the root page settings.

References

https://contao.org/en/security-advisories/cross-site-scripting-via-canonical-url

For more information

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

Impact

When a front end member changes their password, the corresponding remember-me tokens are not removed.

Patches

Update to Contao 4.13.40.

Workarounds

Disable "Allow auto login" in the login module.

References

https://contao.org/en/security-advisories/remember-me-tokens-are-not-cleared-after-a-password-change

For more information

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

Multiple cross-site request forgery (CSRF) vulnerabilities in main.php in Contao (formerly TYPOlight) 2.11.0 and earlier allow remote attackers to hijack the authentication of administrators for requests that (1) delete users via a delete action in the user module, (2) delete news via a delete action in the news module, or (3) delete newsletters via a delete action in the newsletters module.

Impact

Backend users with precise control over the contents of template closures can execute arbitrary PHP functions that do not have required parameters.

Patches

Update to Contao 4.13.57, 5.3.42 or 5.6.5

Workarounds

Manually patch the Contao\Template::once() method.

Resources

https://contao.org/en/security-advisories/remote-code-execution-in-template-closures

Impact

Authenticated users can inject malicious code in widgets with units, which is then executed both in the element preview (back end) and on the website (front end).

Patches

Update to Contao 4.9.42, 4.13.28 or 5.1.10.

Workarounds

Disable login for all untrusted back end users.

References

https://contao.org/en/security-advisories/cross-site-scripting-in-widgets-with-units

For more information

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

Credits

Thanks to Christian Pöschl and Fabian Brenner from usd AG for reporting this vulnerability.

Contao is an open source content management system. Prior to versions 4.9.40, 4.13.21, and 5.1.4, logged in users can list arbitrary system files in the file manager by manipulating the Ajax request. However, it is not possible to read the contents of these files. Users should update to Contao 4.9.40, 4.13.21 or 5.1.4 to receive a patch. There are no known workarounds.

Contao 3.x before 3.5.37, 4.4.x before 4.4.31 and 4.6.x before 4.6.11 has Incorrect Access Control.

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-vqqr-fgmh-f626. This link is maintained to preserve external references.

Original Description

Contao 5.4.1 allows an authenticated admin account to upload a SVG file containing malicious javascript code into the target system. If the file is accessed through the website, it could lead to a Cross-Site Scripting (XSS) attack or execute arbitrary code via a crafted javascript to the target.

Impact

It is possible to inject code into the tllog table that will be executed in the browser when the system log is called in the back end.

Patches

Update to Contao 4.9.16 or 4.11.5.

Workarounds

Disable the system log module in the back end for all users (especially admin users).

References

https://contao.org/en/security-advisories/cross-site-scripting-in-the-system-log-2021

For more information

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

Contao before 4.5.7 has XSS in the system log.

Contao 3.x before 3.5.32 allows Cross-site Scripting (XSS) via the unsubscribe module in the frontend newsletter extension.

Impact

It is possible for untrusted users to inject malicious code into HTML attributes in the back end, which will be executed both in the element preview (back end) and on the website (front end).

Installations are only affected if there are untrusted back end users who have the rights to modify HTML fields (e.g. TinyMCE).

Patches

Update to Contao 4.4.56, 4.9.18 or 4.11.7

Workarounds

Disable all fields that allow HTML for untrusted back end users or disable the login for these users.

References

https://contao.org/en/security-advisories/cross-site-scripting-via-html-attributes-in-the-back-end

For more information

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

Credits

Thanks to Mikhail Khramenkov and Moritz Vondano for reporting this security issue.

Impact

Users can insert malicious code into file names when uploading files, which is then executed in tooltips and popups in the backend.

Patches

Update to Contao 4.13.40 or Contao 5.3.4.

Workarounds

Disable uploads for untrusted users.

References

https://contao.org/en/security-advisories/cross-site-scripting-in-the-file-manager

For more information

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

Credits

Thanks to Alexander Wuttke for reporting this vulnerability.

Impact

It is possible to inject insert tags via the form generator if the submitted form data is output on the page in a specific way.

Patches

Update to Contao 4.13.40 or 5.3.4.

Workarounds

Do not output the submitted form data on the website.

References

https://contao.org/en/security-advisories/insert-tag-injection-via-the-form-generator

For more information

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

Impact

It is possible to inject insert tags in canonical URLs which will be replaced when the page is rendered.

Patches

Update to Contao 4.13.49, 5.3.15 or 5.4.3.

Workarounds

Disable canonical tags in the settings of the website root page.

References

https://contao.org/en/security-advisories/insert-tag-injection-via-canonical-urls

For more information

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