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Arbitrary file deletion via attacker-controlled clear_<attr>[] in HasUploadFields::uploadMultipleFilesToDisk

High
tabacitu published GHSA-8xjm-wqrp-2f25 Jun 15, 2026

Package

composer backpack/crud (Composer)

Affected versions

>= 5.0.0, < 6.0.0
>= 6.0.0, < 6.8.12
>= 7.0.0, < 7.0.35

Patched versions

6.8.12
7.0.35

Description

Summary

HasUploadFields::uploadMultipleFilesToDisk (in src/app/Models/Traits/HasUploadFields.php) reads file paths from the clear_<attribute>[] request input and deletes them from the configured storage disk without verifying that the paths belong to the current model record.

An authenticated user with Update access on any CRUD that wires uploadMultipleFilesToDisk as a model mutator (the pattern documented in the v5.x upload_multiple field guide) can supply arbitrary disk-relative paths in clear_<attr>[] to delete files that were never associated with the record they are editing.

The safe pattern already exists in the codebase: src/app/Library/Uploaders/MultipleFiles.php intersects the requested deletions against the files currently stored in the database column before calling Storage::disk()->delete(). The trait method lacks that intersection.

Affected code

  • src/app/Models/Traits/HasUploadFields.php — uploadMultipleFilesToDisk (primary sink)
  • src/app/Models/Traits/CrudTrait.php — mixes HasUploadFields into all Backpack-managed models

The vulnerability is present in all 5.x, 6.x < 6.8.12, and 7.x < 7.0.35 releases.

Impact

An attacker with low-privilege Backpack admin access (e.g. a content editor) can delete any file under the configured disk root: other records' attachments, shared assets, or files placed on the same disk for operational purposes. No confidentiality impact (files cannot be read, only deleted).

CWE-285 (Authorization Bypass) / CWE-639 (IDOR on file deletion)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H = 8.1 High

Fix

Intersect $files_to_clear against the filenames currently persisted on the model before calling delete(), mirroring the logic already present in MultipleFiles::uploadFiles. Fixed in 6.8.12 and 7.0.35.

Deployments still using the uploadMultipleFilesToDisk mutator pattern from the v5.x docs should migrate to the Uploader API (MultipleFiles::class via config/backpack/crud.php), which applies the safe intersection automatically.

Credits

Reported by Vishal Shukla (@shukla304).

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

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

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

CVE ID

CVE-2026-54178

Weaknesses

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. Learn more on MITRE.

Improper Authorization

The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Learn more on MITRE.

Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. Learn more on MITRE.

Credits