CVE-2024-56145: Craft CMS Code Injection Vulnerability

CVE-2024-56145 is a code injection vulnerability in Craft CMS that can allow remote code execution when the PHP configuration option register_argc_argv is enabled. Organizations running Craft CMS should treat this as a high-priority issue because successful exploitation can give an attacker the ability to run arbitrary code on the underlying server, potentially leading to full system compromise, data theft, or further lateral movement.

Public detail is limited to the CISA description and the associated CWE; exact affected versions, attack vectors, and scoring must be confirmed against the vendor advisory before making final risk decisions.

How it works

The vulnerability is classified as CWE-94, Improper Control of Generation of Code (Code Injection). In this class of flaw, an application fails to properly sanitize or restrict input that is later used to generate or execute code. For Craft CMS, the CISA summary states that users of affected versions become vulnerable to remote code execution specifically when their php.ini configuration has register_argc_argv enabled.

An attacker who can supply crafted input that reaches the vulnerable code path can cause the application to interpret that input as executable PHP. The register_argc_argv setting makes command-line style arguments available to PHP scripts even in a web context, which can expand the ways injected code is processed. No further exploit mechanics are provided in the available facts; defenders should assume that any unauthenticated or low-privilege request path capable of reaching the injection point could be abused until the vendor advisory is reviewed for precise conditions.

Am I affected? How to find it in your systems

Craft CMS is a PHP-based content management system commonly used to power public-facing websites, marketing sites, and digital experience platforms. It typically runs on Linux or Windows web servers under Apache, Nginx, or similar, often behind a reverse proxy or load balancer, and stores content in a relational database.

• Inventory all web properties and internal applications that use Craft CMS by examining package managers, composer.lock files, deployment manifests, container images, and configuration management databases.
• Identify the installed Craft CMS version on each instance and compare it against the list of affected versions published in the vendor advisory; do not rely on version numbers not present in that advisory.
• Inspect the active php.ini (or equivalent PHP-FPM / Apache module configuration) for the register_argc_argv directive. If it is set to On, the system meets the condition described by CISA and is at elevated risk if the Craft CMS version is affected.
• Review web server and application logs for unusual request patterns that might indicate probing or exploitation attempts, such as unexpected query parameters, POST bodies containing PHP-like constructs, or anomalous process spawning from the web server user. Because specific indicators of compromise are not supplied in the facts, treat any anomalous activity involving Craft CMS as warranting investigation.

How to remediate

The primary remediation is to apply the vendor-supplied update for Craft CMS exactly as directed in the official advisory. CISA’s required action is to apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

• After patching, verify that the updated version is running and that register_argc_argv is set to Off unless a documented operational need requires it; disabling the setting removes the enabling condition described by CISA.
• Harden the PHP environment by ensuring other dangerous settings (allow_url_include, display_errors in production, etc.) follow least-privilege and secure-defaults practices recommended for PHP applications.
• Confirm that the web server process runs with minimal privileges and that the Craft CMS installation directory and configuration files are not writable by the web server user.

If you can't patch immediately

Until the vendor update can be applied, reduce exposure with compensating controls appropriate to a code-injection / remote-code-execution class vulnerability.

• Network segmentation: place Craft CMS instances in a restricted VLAN or security group that allows only necessary inbound traffic from trusted reverse proxies or load balancers and blocks direct internet access where possible.
• Virtual patching / WAF: deploy or tune a web application firewall to block requests that attempt to inject code or that match known patterns for this class of attack; confirm rule efficacy against the vendor’s description of the issue.
• Disable the enabling condition: set register_argc_argv = Off in php.ini (or the equivalent runtime configuration) and restart PHP-FPM or the web server; this directly addresses the condition stated by CISA.
• Monitoring: increase logging verbosity for the Craft CMS application and the PHP process, and alert on unexpected process creation, outbound connections, or file modifications under the web root.
• If the instance is not business-critical, consider temporarily taking it offline or replacing it with a static alternative until patching is complete.

If your data may have been exposed

Actively exploited remote-code-execution vulnerabilities frequently result in data breaches, credential theft, or installation of further malware. Ransomware use associated with this CVE is not documented in the available facts. If you suspect compromise, isolate the affected systems, preserve logs and forensic images, and follow your incident-response plan. As a quick additional check, you can run a free exposure scan of your email addresses against known breach data sets to determine whether any of your accounts already appear in public breach collections.