CVE-2022-24800 (published 2022-07-12T20:15Z)

October/System is the system module for October CMS, a self-hosted CMS platform based on the Laravel PHP Framework. Prior to versions 1.0.476, 1.1.12, and 2.2.15, when the developer allows the user to specify their own filename in the `fromData` method, an unauthenticated user can perform remote code execution (RCE) by exploiting a race condition in the temporary storage directory. This vulnerability affects plugins that expose the `October\\Rain\\Database\\Attach\\File::fromData` as a public interface and does not affect vanilla installations of October CMS since this method is not exposed or used by the system internally or externally. The issue has been patched in Build 476 (v1.0.476), v1.1.12, and v2.2.15. Those who are unable to upgrade may apply with patch to their installation manually as a workaround.

Severity: MEDIUM
CVSS v2 base score: 6.8 (AV:N/AC:M/Au:N/C:P/I:P/A:P)
CVSS v3 base score: 8.1, HIGH (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-362
cwe_name: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
description: The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.
extended_description: 
            This can have security implications when the expected synchronization is in security-critical code, such as recording whether a user is authenticated or modifying important state information that should not be influenced by an outsider.
            A race condition occurs within concurrent environments, and is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc.
            A race condition violates these properties, which are closely related:
               
                  Exclusivity - the code sequence is given exclusive access to the shared resource, i.e., no other code sequence can modify properties of the shared resource before the original sequence has completed execution.
                  Atomicity - the code sequence is behaviorally atomic, i.e., no other thread or process can concurrently execute the same sequence of instructions (or a subset) against the same resource.
               
            A race condition exists when an "interfering code sequence" can still access the shared resource, violating exclusivity. Programmers may assume that certain code sequences execute too quickly to be affected by an interfering code sequence; when they are not, this violates atomicity. For example, the single "x++" statement may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read (the original value of x), followed by a computation (x+1), followed by a write (save the result to x).
            The interfering code sequence could be "trusted" or "untrusted." A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.
         
         

Fix information:
repo_url: https://github.com/octobercms/library
commit_details: repo_url: https://github.com/octobercms/library
author: Sam Georges
author_date: 2022-03-29 12:51:19+11:00
msg: Refactor
repository: repo_url: https://github.com/octobercms/library
repo_name: octobercms/library
description: October Rain Library
repo_language: PHP
owner: octobercms
file_changes: filename: File.php
change_type: ModificationType.MODIFY
diff: @@ -124,14 +124,14 @@ class File extends Model
     /**
      * fromFile creates a file object from a file on the disk
      */
-    public function fromFile($filePath)
+    public function fromFile($filePath, $filename = null)
     {
         if ($filePath === null) {
             return;
         }
 
         $file = new FileObj($filePath);
-        $this->file_name = $file->getFilename();
+        $this->file_name = empty($filename) ? $file->getFilename() : $filename;
         $this->file_size = $file->getSize();
         $this->content_type = $file->getMimeType();
         $this->disk_name = $this->getDiskName();
@@ -152,10 +152,11 @@ class File extends Model
             return;
         }
 
-        $tempPath = temp_path(basename($filename));
+        $tempName = str_replace('.', '', uniqid('', true)) . '.tmp';
+        $tempPath = temp_path($tempName);
         FileHelper::put($tempPath, $data);
 
-        $file = $this->fromFile($tempPath);
+        $file = $this->fromFile($tempPath, basename($filename));
         FileHelper::delete($tempPath);
 
         return $file;

programming_language: PHP