The Keep Backup Daily plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the backup title alias (`val` parameter) in the `update_kbd_bkup_alias` AJAX action in all versions up to, and including, 2.1.2. This is due to insufficient input sanitization and output escaping. While `sanitize_text_field()` strips HTML tags on save, it does not encode double quotes.
The backup titles are output in HTML attribute contexts without `esc_attr()`. This makes it possible for authenticated attackers, with Administrator-level access and above, to inject arbitrary web scripts via attribute injection that will execute whenever another administrator views the backup list page.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
High
Admin privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 6
https://plugins.trac.wordpress.org/browser/keep-backup-daily/tags/2.1.1/inc/fun…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/keep-backup-daily/tags/2.1.1/inc/kbd…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/keep-backup-daily/trunk/inc/function…
security@wordfence.com
https://plugins.trac.wordpress.org/browser/keep-backup-daily/trunk/inc/kbd_cron…
security@wordfence.com
https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&ol…
security@wordfence.com
https://www.wordfence.com/threat-intel/vulnerabilities/id/18a4fa4b-5c99-4347-8b…
security@wordfence.com