Vulnerabilities

Grav is a file-based Web platform. Prior to 2.0.0, an authenticated admin.super user can crash Grav or fill the disk by uploading a specially crafted ZIP archive through the Direct Install tool because Installer::unZip calls ZipArchive::extractTo without limits on uncompressed size, entry count, or directory depth. This issue is fixed in version 2.0.0.

Grav before 1.6.30 contains a cross-site scripting vulnerability in the Admin plugin page editor default security configuration. Privileged users with page editing capabilities can inject malicious scripts to execute arbitrary code and install malicious plugins for system access.

Grav is a file-based Web platform. In Grav 2.0.0-beta.2, a low-privileged authenticated API user with api.media.write can abuse /api/v1/blueprint-upload to write an arbitrary YAML file into user/accounts/, then log in as the newly created account with api.super privileges. This results in full administrative compromise of the Grav API. This vulnerability is fixed in API 1.0.0-beta.17.

Grav is a file-based Web platform. Prior to 2.0.0-beta.2, a low-privileged (with the ability to create a page) user can cause XSS with the injection of svg element. The XSS can further be escalated to dump the entire system information available under /admin/config/info whenever a Super Admin visits the page; which can further be chained with the use of admin-nonce to do a complete server compromise (RCE). This vulnerability is fixed in 2.0.0-beta.2.

Grav API Plugin is a RESTful API for Grav CMS that provides full headless access to your site's content, media, configuration, users, and system management. Prior to 1.0.0-beta.15, an insecure direct object reference and logic flaw in the Grav API plugin (UsersController::update) allows any authenticated user with basic API access (api.access) to modify their own permission configuration. An attacker can exploit this to escalate their privileges to Super Administrator (admin.super and api.super), leading to full system compromise and potential RCE. This vulnerability is fixed in 1.0.0-beta.15.

Grav CMS v1.7.x and before is vulnerable to XML External Entity (XXE) through the SVG file upload functionality in the admin panel and File Manager plugin.

GravCMS 1.10.7 contains an unauthenticated vulnerability that allows remote attackers to write arbitrary YAML configuration and execute PHP code through the scheduler endpoint. Attackers can exploit the admin-nonce parameter to inject base64-encoded payloads and create malicious custom jobs with system command execution.

In grav <1.7.49.5, a SSRF (Server-Side Request Forgery) vector may be triggered via Twig templates when page content is processed by Twig and the configuration allows undefined PHP functions to be registered

Grav CMS 1.7.49 is vulnerable to Cross Site Scripting (XSS). The page editor allows authenticated users to edit page content via a Markdown editor. The editor fails to properly sanitize tags, allowing stored XSS payloads to execute when pages are viewed in the admin interface.

This admin plugin for Grav is an HTML user interface that provides a convenient way to configure Grav and easily create and modify pages. Prior to 1.11.0-beta.1, a Stored Cross-Site Scripting (XSS) vulnerability was identified in the /admin/config/site endpoint of the Grav application. This vulnerability allows attackers to inject malicious scripts into the data[taxonomies] parameter. The injected payload is stored on the server and automatically executed in the browser of any user who accesses the affected site configuration, resulting in a persistent attack vector. This vulnerability is fixed in 1.11.0-beta.1.

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, Grav CMS is vulnerable to a Server-Side Template Injection (SSTI) that allows any authenticated user with editor permissions to execute arbitrary code on the remote server, bypassing the existing security sandbox. Since the security sandbox does not fully protect the Twig object, it is possible to interact with it (e.g., call methods, read/write attributes) through maliciously crafted Twig template directives injected into a web page. This allows an authenticated editor to add arbitrary functions to the Twig attribute system.twig.safe_filters, effectively bypassing the Grav CMS sandbox. This vulnerability is fixed in 1.8.0-beta.27.

Grav CMS1.7.49.5 is vulnerable to Cross Site Scripting (XSS).

A Remote Code Execution (RCE) vulnerability in Grav CMS v1.7.48 allows an authenticated admin to upload a malicious plugin via the /admin/tools/direct-install interface. Once uploaded, the plugin is automatically extracted and loaded, allowing arbitrary PHP code execution and reverse shell access.

Cross Site Scripting vulnerability in grav v.1.7.48 and before allows an attacker to execute arbitrary code via a crafted script to the form fields

A cross-site scripting (XSS) vulnerability in Grav v1.7.45 allows attackers to execute arbitrary web scripts or HTML via a crafted payload.

Grav is a file-based Web platform. Prior to version 1.7.46, a low privilege user account with page edit privilege can read any server files using Twig Syntax. This includes Grav user account files - `/grav/user/accounts/*.yaml`. This file stores hashed user password, 2FA secret, and the password reset token. This can allow an adversary to compromise any registered account and read any file in the web server by resetting a password for a user to get access to the password reset token from the file or by cracking the hashed password. A low privileged user may also perform a full account takeover of other registered users including Administrators. Version 1.7.46 contains a patch.

Grav is an open-source, flat-file content management system. A file upload path traversal vulnerability has been identified in the application prior to version 1.7.45, enabling attackers to replace or create files with extensions like .json, .zip, .css, .gif, etc. This critical security flaw poses severe risks, that can allow attackers to inject arbitrary code on the server, undermine integrity of backup files by overwriting existing files or creating new ones, and exfiltrate sensitive data using CSS exfiltration techniques. Upgrading to patched version 1.7.45 can mitigate the issue.

A cross-site scripting (XSS) vulnerability in Grav versions 1.7.44 and before, allows remote authenticated attackers to execute arbitrary web scripts or HTML via the onmouseover attribute of an ISINDEX element.

DOMSanitizer (aka dom-sanitizer) before 1.0.7 allows XSS via an SVG document because of mishandling of comments and greedy regular expressions.

Grav is a file-based Web-platform built in PHP. Grav is subject to a server side template injection (SSTI) vulnerability. The fix for another SSTI vulnerability using `|map`, `|filter` and `|reduce` twigs implemented in the commit `71bbed1` introduces bypass of the denylist due to incorrect return value from `isDangerousFunction()`, which allows to execute the payload prepending double backslash (`\\`). The `isDangerousFunction()` check in version 1.7.42 and onwards retuns `false` value instead of `true` when the `\` symbol is found in the `$name`. This vulnerability can be exploited if the attacker has access to: 1. an Administrator account, or 2. a non-administrator, user account that has Admin panel access and Create/Update page permissions. A fix for this vulnerability has been introduced in commit `b4c6210` and is included in release version `1.7.42.2`. Users are advised to upgrade. There are no known workarounds for this vulnerability.