In certain scenarios, Drupal's JSON:API module will output error backtraces. With some configurations, this may cause sensitive information to be cached and made available to anonymous users, leading to privilege escalation. This vulnerability only affects sites with the JSON:API module enabled, and can be mitigated by uninstalling JSON:API. The core REST and contributed GraphQL modules are not affected.

The file download facility doesn't sufficiently sanitize file paths in certain situations. This may result in users gaining access to private files that they should not have access to. Some sites may require configuration changes following this security release. Review the release notes for your Drupal version if you have issues accessing private files after updating.

Under certain circumstances, the Drupal core form API evaluates form element access incorrectly. This may lead to a user being able to alter data they should not have access to. No forms provided by Drupal core are known to be vulnerable. However, forms added through contributed or custom modules or themes may be affected.

Drupal core sanitizes filenames with dangerous extensions upon upload (reference: SA-CORE-2020-012) and strips leading and trailing dots from filenames to prevent uploading server configuration files (reference: SA-CORE-2019-010). However, the protections for these two vulnerabilities previously did not work correctly together. As a result, if the site were configured to allow the upload of files with an htaccess extension, these files' filenames would not be properly sanitized. This could allow bypassing the protections provided by Drupal core's default .htaccess files and possible remote code execution on Apache web servers. This issue is mitigated by the fact that it requires a field administrator to explicitly configure a file field to allow htaccess as an extension (a restricted permission), or a contributed module or custom code that overrides allowed file uploads.

The Media oEmbed iframe route does not properly validate the iframe domain setting, which allows embeds to be displayed in the context of the primary domain. Under certain circumstances, this could lead to cross-site scripting, leaked cookies, or other vulnerabilities.

In some situations, the Image module does not correctly check access to image files not stored in the standard public files directory when generating derivative images using the image styles system. Access to a non-public file is checked only if it is stored in the "private" file system. However, some contributed modules provide additional file systems, or schemes, which may lead to this vulnerability. This vulnerability is mitigated by the fact that it only applies when the site sets (Drupal 9) $config['image.settings']['allow_insecure_derivatives'] or (Drupal 7) $conf['image_allow_insecure_derivatives'] to TRUE. The recommended and default setting is FALSE, and Drupal core does not provide a way to change that in the admin UI. Some sites may require configuration changes following this security release. Review the release notes for your Drupal version if you have issues accessing files or image styles after updating.

Twig is a template language for PHP. Versions 1.x prior to 1.44.7, 2.x prior to 2.15.3, and 3.x prior to 3.4.3 encounter an issue when the filesystem loader loads templates for which the name is a user input. It is possible to use the `source` or `include` statement to read arbitrary files from outside the templates' directory when using a namespace like `@somewhere/../some.file`. In such a case, validation is bypassed. Versions 1.44.7, 2.15.3, and 3.4.3 contain a fix for validation of such template names. There are no known workarounds aside from upgrading.

Guzzle is an open source PHP HTTP client. In affected versions `Authorization` headers on requests are sensitive information. On making a request using the `https` scheme to a server which responds with a redirect to a URI with the `http` scheme, we should not forward the `Authorization` header on. This is much the same as to how we don't forward on the header if the host changes. Prior to this fix, `https` to `http` downgrades did not result in the `Authorization` header being removed, only changes to the host. Affected Guzzle 7 users should upgrade to Guzzle 7.4.4 as soon as possible. Affected users using any earlier series of Guzzle should upgrade to Guzzle 6.5.7 or 7.4.4. Users unable to upgrade may consider an alternative approach which would be to use their own redirect middleware. Alternately users may simply disable redirects all together if redirects are not expected or required.

Guzzle is an open source PHP HTTP client. In affected versions the `Cookie` headers on requests are sensitive information. On making a request using the `https` scheme to a server which responds with a redirect to a URI with the `http` scheme, or on making a request to a server which responds with a redirect to a a URI to a different host, we should not forward the `Cookie` header on. Prior to this fix, only cookies that were managed by our cookie middleware would be safely removed, and any `Cookie` header manually added to the initial request would not be stripped. We now always strip it, and allow the cookie middleware to re-add any cookies that it deems should be there. Affected Guzzle 7 users should upgrade to Guzzle 7.4.4 as soon as possible. Affected users using any earlier series of Guzzle should upgrade to Guzzle 6.5.7 or 7.4.4. Users unable to upgrade may consider an alternative approach to use your own redirect middleware, rather than ours. If you do not require or expect redirects to be followed, one should simply disable redirects all together.

Cross-site request forgery (CSRF) vulnerability in the Content Lock module for Drupal allows remote attackers to hijack the authentication of unspecified victims via unknown vectors.

The Contact Forms module 7.x-1.x before 7.x-1.2 for Drupal does not specify sufficiently restrictive permissions, which allows remote authenticated users with the "access the site-wide contact form" permission to modify the module settings via unspecified vectors.

Cross-site scripting (XSS) vulnerability in the Glossary module 6.x-1.x before 6.x-1.8 for Drupal allows remote attackers to inject arbitrary web script or HTML via unspecified vectors related to "taxonomy information."

Cross-site scripting (XSS) vulnerability in the aberdeen_breadcrumb function in template.php in the Aberdeen theme 6.x-1.x before 6.x-1.11 for Drupal, when set to append the content title to the breadcrumb, allows remote attackers to inject arbitrary web script or HTML via the content title in a breadcrumb.

Cross-site request forgery (CSRF) vulnerability in the Take Control module 6.x-2.x before 6.x-2.2 for Drupal allows remote attackers to hijack the authentication of unspecified users for Ajax requests that manipulate files.

SQL injection vulnerability in the Views module before 6.x-2.13 for Drupal allows remote attackers to execute arbitrary SQL commands via vectors related to "filters/arguments on certain types of views with specific configurations of arguments."

Multiple cross-site scripting (XSS) vulnerabilities in revisioning_theme.inc in the Taxonomy module in the Revisioning module 6.x-3.13 and other versions before 6.x-3.14 for Drupal allow remote authenticated users with certain privileges to inject arbitrary web script or HTML via the (1) tags or (2) term parameters.

Cross-site request forgery (CSRF) vulnerability in the clickthrough tracking functionality in the Forward module 6.x-1.x before 6.x-1.21 and 7.x-1.x before 7.x-1.3 for Drupal allows remote attackers to hijack the authentication of administrators for requests that increase node rankings via the tracking code, possibly related to improper "flood control."

The Forward module 6.x-1.x before 6.x-1.21 and 7.x-1.x before 7.x-1.3 for Drupal does not properly enforce permissions for (1) Recent forwards, (2) Most forwarded, or (3) Dynamic blocks, which allows remote attackers to obtain node titles via unspecified vectors.

Cross-site scripting (XSS) vulnerability in display_renderers/panels_renderer_editor.class.php in the admin view in the Panels module 6.x-2.x before 6.x-3.10 and 7.x-3.x before 7.x-3.0 for Drupal allows remote authenticated users with certain privileges to inject arbitrary web script or HTML via the Region title.

Cross-site scripting (XSS) vulnerability in the Meta tags quick module 7.x-2.x before 7.x-2.3 for Drupal allows remote authenticated users with certain permissions to inject arbitrary web script or HTML via unspecified vectors, probably related to "names of entity bundles."