Grav vulnerabilities

Grav 2.0.0 through 2.0.24 contain a Twig content sandbox escape. The `array` filter is allowlisted but lacks the sandbox guard, allowing access to the raw DI container and disclosure of the full configuration tree, including credentials and secrets, to anonymous visitors.

Grav before 2.0.14 fails to guard the access field in the core group blueprint with the required security@: admin.super restriction. A delegated admin.users operator can save a group with access[admin][super]=true to escalate to super-admin, gaining scheduler and Twig evaluation capabilities.

Grav 2.0.4 (fixed in 2.0.7) contains a remote code execution vulnerability in Blueprint::dynamicData(). The function passes a Class::method callable string and its arguments directly to call_user_func_array() without any allowlist. Because the form plugin routes page frontmatter through this path, an authenticated account with admin.pages (or api.pages.write) permission can plant a malicious callable directive in a page. The command executes as the web-server user whenever anyone – including an unauthenticated visitor – accesses the page.

Grav before version 2.0.2 contains a Twig sandbox bypass that allows a page author (any admin.pages user, or anyone able to write to user/pages) to exfiltrate configuration secrets. Although the sandbox replaces the 'config' variable with a redacted facade and strips Config::get/toArray from the method allowlist, the raw container remains accessible via the allow-listed grav.offsetGet('config'), which returns the real Config object. Allow-listed object-dumping filters (json_encode, print_r, yaml_encode) then serialize that object at the PHP level without invoking the sandbox method gate, exposing the full config tree including plugin secrets such as SMTP credentials, API keys, and plugin DB credentials.

In grav before 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 is a file-based Web platform. Prior to 1.8.0-beta.27, due to improper authorization checks when modifying critical fields on a POST request to /admin/pages/{page_name}, an editor with only permissions to change basic content on the form is now able to change the functioning of the form through modifying the content of the data[_json][header][form] which is the YAML frontmatter which includes the process section which dictates what happens after a user submits the form which include some important actions that could lead to further vulnerabilities. This vulnerability is fixed in 1.8.0-beta.27.

Grav from 1.7.53.3 before 1.7.53.6 contains an authorization bypass in Debugger::isDebuggerRequestAuthorized() that allows unauthenticated visitors to read /__clockwork/ profiler data via a loopback REMOTE_ADDR fallback. Behind a same-host reverse proxy, remote requests appear as loopback, letting attackers read stored records including administrator plaintext passwords and configuration credentials.

Grav 2.0.15 before 2.2.13 contains an allowlist bypass vulnerability that allows page editors to invoke arbitrary public static methods by relocating data-*@ directives with unset-name@ or integer keys. Attackers with page-edit permission can embed crafted fields in Flex form overrides in page frontmatter to call methods like Folder::delete or Utils::download, deleting directories, overwriting files, or reading files outside the page tree.

Grav from 2.0.0 before 2.2.5 contains an improper access control vulnerability in FlexDirectory::dynamicFlexField() that allows page authors to call arbitrary Flex object methods via flex-*@ directives in page frontmatter. When a user with page edit rights opens the page, directives calling setStorageKey() and delete() run in their session, deleting protected pages neither account may delete.

Grav from 2.0.0 before 2.2.5 contains an information disclosure vulnerability that allows page authors to capture visitors' HTTP Basic credentials through Twig page content. Authors can print the request Uri object, which embeds PHP_AUTH_USER and PHP_AUTH_PW, inside an inline style background image to exfiltrate administrators' credentials to an external host.

Grav 1.7.53 before 1.7.53.5 and 2.0.0-rc.8 before 2.2.2 contain a resource exhaustion vulnerability that allows anonymous visitors to bypass the system.images.max_pixels limit when system.images.url_actions is enabled. Attackers can send single-dimension or percentage forceResize, zoomCrop, or chained image actions to make GD allocate multi-gigabyte canvases, exhausting server memory and taking the site down.

Grav from 2.0.0 before 2.2.2 allows page editors to read protected configuration by adding config-*@ directives to page frontmatter forms. Attackers with page-edit permission can bypass the Twig sandbox config_denied_paths redaction to expose security.salt, plugin credentials, and Redis passwords to all visitors.

Grav from 2.0.15 before 2.2.2 contains an allowlist bypass vulnerability that allows page editors to call arbitrary public static methods by renaming Flex form fields with replace-name@. Attackers with page-edit permission can smuggle data-*@ directives past the callable check to invoke Folder::delete, Folder::move, or Utils::download, deleting directories, overwriting files, or reading files.

Grav before 2.1.7 contains an information disclosure vulnerability because bundled nginx, lighttpd, IIS, and Caddy 2 configurations block .git only at document root. Unauthenticated attackers can request nested repositories such as user/.git to retrieve Git config, refs, and objects, reconstructing unpublished history or committed secrets.

Grav from 2.0.22 before 2.1.7 contains an authentication bypass vulnerability in the Clockwork profiler that trusts loopback REMOTE_ADDR values. Unauthenticated attackers behind a same-host HTTP proxy can read profiler records exposing system and plugin configuration, secrets, request metadata, and queries.

Grav before 2.1.7 contains a denial of service vulnerability that allows authenticated media authors to exhaust memory by uploading compressed oversized raster images. Attackers can reference a Twig or Markdown transform so GD or Imagick decodes the full source without dimension checks, letting anonymous requests repeatedly cause page unavailability.

Grav from 2.0.22 before 2.1.7 contains an information disclosure vulnerability that allows page editors to read the Clockwork debugger token because the sandbox redaction list omits system.debugger.token. Attackers can render the token through editor-authored Twig and supply it as X-Clockwork-Auth to read profiler records with configuration, request metadata, and database queries.

Grav is a flat-file CMS. In versions 2.0.19 through 2.0.24 — and in 2.0.0 through 2.0.18 and 1.7.x only where content Twig has been explicitly enabled — page content authored by a user holding only page-write permission is rendered through a Twig sandbox that allowlists get_cookie(), which returns any cookie sent with the current request, including the visitor's session cookie. Grav then stores the finished post-Twig output in a page-content cache keyed only on page identity and the configuration checksum, with no session, user or request dimension.

Grav before 2.0.25 ships web server configuration samples whose access-control deny rules are matched case-sensitively. In web.config (IIS), every deny rule sets ignoreCase="false", allowing bypass by varying case in folder names or file extensions. On case-insensitive NTFS, an unauthenticated remote attacker can access sensitive files like configuration secrets or password hashes.

Grav is a flat-file CMS. In versions 2.0.0-rc.1 through 2.0.21, the Twig content sandbox fails to restrict the dump and serialize filters (print_r, vardump, json_encode, yaml_encode, string) because GravExtension::assertSandboxDumpSafe() checks sandbox state without a Source argument, so the guard never executes. An authenticated user with page-edit rights can render {{ config|print_r }} and dump Grav's entire merged configuration, exposing plugin secrets such as SMTP credentials, API tokens, webhook secrets and cache backend passwords.

In Grav (a flat-file CMS) versions 1.7.0 through 1.7.53.2 and 2.0.0 through 2.0.21, when the debugger is enabled (system.debugger.enabled: true, which is not the default), the Clockwork profiler endpoint at /__clockwork/ is exposed without authentication. Because the shipped default is censored: false, stored records contain raw session cookies, plaintext login credentials, and the full system and plugin configuration including operator secrets. The issue is fixed in 1.7.53.4 and 2.0.22.

Grav 1.7.50.2 allows admins to enter JavaScript via the Home Page editor. The relevance of this for stored XSS is disputed because admins are allowed to modify templates, install plugins, and upload other executable content.

Grav before 2.0.20 contains a cross-site scripting vulnerability in the Twig sandbox policy that allows addJs and addCss methods on Grav\Common\Assets without proper output escaping. Page editors can inject arbitrary script by registering malicious assets or injecting attributes, which are rendered unescaped into document head tags and executed for all visitors including administrators.

Grav before 2.0.18 (affected versions <= 2.0.17) contains a remote code execution vulnerability in the Twig sort filter. The sortFunc wrapper in GravExtension.php hardcodes Twig's isSandboxed argument to false, allowing a plain function name inside the sandbox; the remaining denylist misses spl_autoload, which performs a PHP include. An authenticated user with only page-write rights can supply a crafted payload, resulting in arbitrary PHP execution as the web server user.

Grav versions before 1.10.55 contain a path traversal vulnerability in the admin plugin's Save As action that fails to validate the language code parameter. An authenticated admin user with admin.pages.create permission can supply directory traversal sequences in the lang POST field to write arbitrary .md files outside the pages directory with attacker-controlled content.

Grav versions 2.0.0 through 2.0.17 fail to apply save-time XSS detection to modular pages, allowing authenticated page editors to store Twig-assembled XSS payloads. Attackers with page-edit rights can create modular pages with malicious Twig code that executes in visitor browsers when the parent page is rendered, including in administrator sessions.

Grav before 2.0.16 contains an incomplete default denylist in the Twig sandbox configuration that fails to block access to system configuration secrets. Attackers with page-edit permission can use config.get() or config.toArray() in Twig templates to retrieve sensitive values like system.cache.redis.password when config_access is enabled.

Grav before 2.0.16 allows sandboxed Twig templates to access sensitive User fields through allow-listed offsetGet() and offsetexists() methods that lack field filtering. Attackers with page-edit permissions can call offsetGet() on User objects to extract hashed passwords and 2FA secrets, enabling offline password cracking and authentication bypass.

Grav before 2.0.16 contains a path traversal vulnerability in MediaUploadTrait::deleteFile() that allows authenticated users with media management permissions to delete arbitrary files by supplying filenames with directory traversal sequences. The method validates only the basename portion of the filename while preserving unvalidated directory paths containing ../ sequences that are passed to unlink(), enabling deletion of files outside the intended media storage directory.

Grav before 3.9.2 fails to validate untrusted Host headers in the sendInvitationEmail() function when constructing token-bearing invitation links. Attackers can manipulate the Host header to poison invitation links and redirect users to attacker-controlled domains, bypassing the require_trusted_host protection which only covers password reset flows.

Grav prior to 2.0.7 has a vulnerability in Blueprint::dynamicData() in system/src/Grav/Common/Data/Blueprint.php that sends an editor-controlled Class::method provider and arguments to call_user_func_array() without rejecting dangerous callback parameters. An account with admin.pages or api.pages.write can use Grav\Common\Utils::arrayFilterRecursive() as a trampoline with system as the callback, place a command in page frontmatter, and execute that command as the web server user when the page is viewed. This issue is fixed in version 2.0.7.

Grav before version 2.0.4 contains .htaccess security rules that compare directory and file-extension patterns case-sensitively, without the [NC] flag. On case-insensitive filesystems, an unauthenticated attacker can use uppercase variants to bypass the rules and retrieve files under user/accounts or user/config, including password hashes and security configuration. This issue is fixed in version 2.0.4.

Grav prior to 2.0.4 allowlists the regex_replace filter and function, and GravExtension::regexReplace() passes an editor-controlled pattern directly to preg_replace(). When security.twig_content.process_enabled is enabled, an authenticated page editor can publish a catastrophically backtracking pattern that consumes PHP worker CPU and denies service to site visitors.

Grav prior to 2.0.2 permits grav.offsetGet('config') to return the raw configuration object and allows json_encode, print_r, yaml_encode, and string filters to serialize that object without passing through GravSecurityPolicy::checkMethodAllowed. A user with page-author permissions can render sandboxed content that exposes plugins.* configuration secrets, including SMTP credentials, API keys, and plugin database credentials.

Grav prior to 2.0.1 in ZipArchiver::extract() passes archives to ZipArchive::extractTo() without enforcing the system.gpm.archive uncompressed-size, file-count, or nesting-depth limits. Code using Archiver::create('zip') to extract an attacker-controlled archive can exhaust disk space or inodes and make the site unavailable.

Grav prior to 3.8.5 in the Login plugin twofa_cancel task accepts a client-controlled _redirect field without a nonce and allows an unauthenticated request to set an external http, https, or protocol-relative Location target. Controller::execute() applies the field when taskTwofa_cancel() sets no redirect, and Grav::getRedirectResponse() accepts the target through Uri::isExternal(), enabling phishing redirects from a trusted Grav host.

Grav before 2.0.14 contains a stored cross-site scripting vulnerability in the Security::detectXss() function (system/src/Grav/Common/Security.php). All XSS detection patterns use the PCRE /u (UTF-8) modifier, so a single invalid UTF-8 byte anywhere in page content causes preg_match() to return false for every pattern, silently bypassing the save-time XSS safety gate (Validation::checkSafety()). An authenticated attacker with page-edit permissions (without the security.xss_whitelist privilege) can store malicious JavaScript that executes in the browser of a visitor who views the affected page.

Grav before 2.0.15 contains a stored cross-site scripting vulnerability in the audio and video media rendering through the sourceParsedownElement method. The media URL fragment is concatenated unescaped into rawHtml source elements, allowing attackers to inject arbitrary HTML and JavaScript that executes in viewers' sessions.

Grav before version 2.0.15 contains a stored cross-site scripting vulnerability in the detectXss() function where unpaired quotes in unquoted attribute values bypass event-handler detection. Authenticated editors can inject event handlers like onerror= that pass validation and execute in visitor browsers when page content is rendered.

Grav before version 2.0.15 contains an arbitrary file write vulnerability in the Blueprint dynamic-data bare-function validation that uses an incomplete denylist instead of a positive allowlist. Attackers with page-edit or blueprint-config access can invoke the error_log function through a data directive to append PHP payloads to web-accessible files, achieving remote code execution.

Grav before 2.0.15 contains a path traversal vulnerability in the static asset server within index.php that uses string prefix matching instead of directory-boundary validation. Unauthenticated attackers can access files in sibling directories by exploiting directory names that extend the base path string, such as requesting assets-secret when assets is the configured base.

Grav versions from 1.5.2 through 2.0.12 contain a stored cross-site scripting vulnerability in the Security::detectXss() function (system/src/Grav/Common/Security.php). The event-handler scan is anchored at `<` and uses `[^>]*?`, which cannot cross the first literal `>`; when a `>` appears inside a quoted attribute value the browser keeps the tag open and parses a subsequent event handler (e.g. onerror), so the detector and browser disagree. A page editor without admin.super privileges can save page content such as `<img src=x title=">" onerror=alert(document.domain)>`, which is accepted, stored, and executed in the site origin when any visitor (including unauthenticated users) views the page. Fixed in 2.0.13.

Grav versions before 2.0.13 fail to properly validate backup profile root paths, allowing attackers to archive directories outside GRAV_ROOT when not in the hard-coded deny-list. Attackers with profile editor access can configure backup profiles with traversal paths to expose sensitive files from locations like /opt, /mnt, or /srv.

Remote code execution (RCE) vulnerability in Grav versions 1.7.0 through 2.0.9. FlexDirectory::dynamicDataField() calls call_user_func_array() on attacker-controlled input without restricting dangerous functions like exec or system. An authenticated user with create or update permissions on any Flex directory can execute arbitrary shell commands on the server.

Grav is vulnerable to stored XSS in shortcode attributes because the XSS scan only matches literal angle brackets. An attacker with admin.pages permission can inject malicious JavaScript that executes in any viewer's browser, including administrators.

Grav before version 2.0.4 contains a regular expression denial of service (ReDoS) vulnerability in the regex_replace filter and function, which are allowlisted in the Twig content sandbox. When Twig processing in page content is enabled (disabled by default), an authenticated page editor can supply a catastrophically backtracking PCRE pattern that is passed directly to PHP's preg_replace(), causing unbounded CPU consumption and denial of service to the web server process.

Vulnerability in Grav before version 2.0.4: unrestricted cURL protocols in webhooks. Authenticated users with api.webhooks.write permission can create webhooks with file://, dict://, or gopher:// URLs.

Grav before version 2.0.4 contains a two-factor authentication bypass vulnerability in the login plugin where the regenerate2FASecret task checks only user existence, not authorization, during the pending TOTP challenge window. Attackers who know the victim's password can call this task without a CSRF nonce to overwrite the 2FA secret with an attacker-chosen value, compute a valid TOTP code, and complete authentication while reducing 2FA to password-only protection.

Grav before version 2.0.4 ships a default .htaccess file whose rules blocking access to sensitive file types (.yaml, .php, .json, etc.) lack the [NC] flag, making extension matching case-sensitive. On case-insensitive filesystems (Windows/NTFS, macOS/HFS+, or Docker volume mounts), an unauthenticated attacker can request these files with uppercase or mixed-case extensions (e.g., .YAML, .PHP) to bypass the restrictions and read sensitive configuration files that may contain API keys and credentials.

A vulnerability in Grav before version 9.1.8 allows arbitrary file write via the Form plugin's process.save.filename parameter. Validation before Twig processing is not re-applied after rendering, enabling attackers to bypass checks and write files, including PHP webshells, to the web root or other sensitive directories.