In its default configuration, a Rails application that displays image variants may allow an unauthenticated attacker to read arbitrary files from the server, including the process environment. That environment typically holds secret_key_base and often credentials for external systems, which may in turn allow escalation to remote code execution or lateral movement to those systems.
Active Storage's proxy controller does not limit the number of byte ranges in an HTTP Range header. A request with thousands of small ranges causes disproportionate CPU usage compared to a normal request for the same file, possibly resulting in a DoS vulnerability.
Active Storage's DiskService#path_for does not validate that the resolved filesystem path remains within the storage root directory. If a blob key containing path traversal sequences (e.g. ../) is used, it could allow reading, writing, or deleting arbitrary files on the server. Blob keys are expected to be trusted strings, but some applications could be passing user input as keys and would be affected.
Active Storage's DiskService#delete_prefixed passes blob keys directly to Dir.glob without escaping glob metacharacters. If a blob key contains attacker-controlled input or custom-generated keys with glob metacharacters, it may be possible to delete unintended files from the storage directory.
Active Storage's DirectUploadsController accepts arbitrary metadata from the client and persists it on the blob. Because internal flags like identified and analyzed are stored in the same metadata hash, a malicious direct-upload client could set these flags.
When serving files through Active Storage's Blobs::ProxyController, the controller loads the entire requested byte range into memory before sending it. A request with a large or unbounded Range header (e.g. bytes=0-) could cause the server to allocate memory proportional to the file size, possibly resulting in a DoS vulnerability through memory exhaustion.
Active Storage attempts to prevent the use of potentially unsafe image transformation methods and parameters by default. The default allowed list contains three methods allowing for the circumvention of the safe defaults which enables potential command injection vulnerabilities in cases where arbitrary user supplied input is accepted as valid transformation methods or parameters. This has been assigned the CVE identifier CVE-2025-24293. Versions Affected: >= 5.2.0 Not affected: < 5.2.0 Fixed …
Possible Sensitive Session Information Leak in Active Storage There is a possible sensitive session information leak in Active Storage. By default, Active Storage sends a Set-Cookie header along with the user's session cookie when serving blobs. It also sets Cache-Control to public. Certain proxies may cache the Set-Cookie, leading to an information leak. This vulnerability has been assigned the CVE identifier CVE-2024-26144. Versions Affected: >= 5.2.0, < 7.1.0 Not affected: …
A code injection vulnerability exists in the Active Storage >= v5.2.0 that could allow an attacker to execute code via image_processing arguments.
This advisory duplicates another.
A client side enforcement of server side security vulnerability exists in rails and rails ActiveStorage's S3 adapter that allows the Content-Length of a direct file upload to be modified by an end user bypassing upload limits.
A bypass vulnerability in Active Storage for Google Cloud Storage and Disk services allow an attacker to modify the content-disposition and content-type parameters which can be used in with HTML files and have them executed inline. Additionally, if combined with other techniques such as cookie bombing and specially crafted AppCache manifests, an attacker can gain access to private signed URLs within a specific storage path. This vulnerability has been fixed