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GHSA-xj2c-g5xp-4p47

Duplicate Advisory: Craft CMS: Authenticated "assets/preview-thumb" discloses signed fallback transform preview link to CP users without asset-view permission

Medium Withdrawn Aug 6, 2026 Packagist
Severity
0.0 / 10
Medium · CVSS 4.0
Exploit chance (EPSS)
—
No score published
Known exploited
No
Not in CISA's catalog
Weakness
CWE-862 Missing Authorization
Fix
None yet
No fixed version published

Description

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-x76w-8c62-48mg. This link is maintained to preserve external references.

Original Description

Craft CMS contains a missing authorization vulnerability in the assets/preview-thumb endpoint. A Control Panel user without permission to view a target private asset can call the endpoint with an attacker-controlled assetId and receive preview HTML containing a signed fallback transform preview link for that private asset, because no asset-view permission check is performed before preview generation. This affects versions >= 4.0.0-RC1, <= 4.17.7 and >= 5.0.0-RC1, <= 5.9.13, and is fixed in 4.17.8 and 5.9.14.

Affected versions

Packagist

PackageVulnerableFixed in
craftcms/cms
>= 4.0.0-RC1, <= 4.17.7
No fix yet

How to fix

No fixed version has been published yet. Until one is, remove or replace the package, or turn off or isolate the affected feature. This page updates when a fix ships.

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
Low
User interaction
None
Confidentiality (vulnerable system)
Low
Integrity (vulnerable system)
None
Availability (vulnerable system)
None
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None
Exploit maturity
Not defined
Scope
X

CVSS 3.1 4.3

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

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

Weakness

CWE-862: Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

How to prevent it
  • Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
  • Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
  • 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. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
  • Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
  • System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.

References

Timeline

  1. Published
  2. Withdrawn
  3. Last updated by the source
AdvisorySeverityWhy it's related
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
GHSA-xxpx-f366-4xpq
Craft CMS: Authorization bypass: view-only Categories user can modify category structure via structures/move-element
Medium Also affects craftcms/cms
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