CVE-2026-4853
Vulnérabilité moyenne dans JetBackup – Backup, Restore & Migrate (backupguard)
Description
The JetBackup – Backup, Restore & Migrate plugin for WordPress is vulnerable to Path Traversal leading to Arbitrary Directory Deletion in versions up to and including 3.1.19.8. This is due to insufficient input validation on the fileName parameter in the file upload handler. The plugin sanitizes the fileName parameter using sanitize_text_field(), which removes HTML tags but does not prevent path traversal sequences like '../'. The unsanitized filename is then directly concatenated in Upload::getFileLocation() without using basename() or validating the resolved path stays within the intended directory. When an invalid file is uploaded, the cleanup logic calls dirname() on the traversed path and passes it to Util::rm(), which recursively deletes the entire resolved directory. This makes it possible for authenticated attackers with administrator-level access to traverse outside the intended upload directory and trigger deletion of critical WordPress directories such as wp-content/plugins, effectively disabling all installed plugins and causing severe site disruption.
Gravité et risque d'exploitation
CVE-2026-4853 obtient un score CVSS de 4.9/10, soit une gravité moyenne. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.60 %, ce qui la place devant 48.0 % des CVE référencées.
Que faire ?
- Vérifiez si JetBackup – Backup, Restore & Migrate (versions 0, <=3.1.19.8) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://www.wordfence.com/threat-intel/vulnerabilities/id/4aa0fa80-05dd-4fe1-b7b5-7ed0cf13053c?source=cve
- https://plugins.trac.wordpress.org/browser/backup/trunk/src/JetBackup/Upload/Upload.php#L66
- https://plugins.trac.wordpress.org/browser/backup/tags/3.1.17.5/src/JetBackup/Upload/Upload.php#L66
- https://plugins.trac.wordpress.org/browser/backup/trunk/src/JetBackup/Ajax/Calls/AddToQueue.php#L64
- https://plugins.trac.wordpress.org/browser/backup/tags/3.1.17.5/src/JetBackup/Ajax/Calls/AddToQueue.php#L64
- https://plugins.trac.wordpress.org/browser/backup/trunk/src/JetBackup/Ajax/Calls/AddToQueue.php#L244
- https://plugins.trac.wordpress.org/browser/backup/tags/3.1.17.5/src/JetBackup/Ajax/Calls/AddToQueue.php#L244
- https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3495633%40backup&new=3495633%40backup&sfp_email=&sfph_mail=
