Bears Backup <= 2.0.0 - Unauthenticated Remote Code Execution
Strategic Overview
- Status
- Patched in 2.1.0
- Affected Plugin
- Bears Backup
- Affected Version
<= 2.0.0- CVSS
- 9.8Critical
- Weakness type
- CWE-94 · Improper Control of Generation of Code ('Code Injection')
- CVE
CVE-2025-5396
At a glance
CVE-2025-5396 is a critical-severity Improper Control of Generation of Code ('Code Injection') vulnerability in the Bears Backup WordPress plugin, affecting versions <= 2.0.0. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 2.1.0; sites on affected versions should update now. Disclosed July 2025, reported by Trương Hữu Phúc (truonghuuphuc).
Vulnerability Overview
The Bears Backup plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 2.0.0. This is due to the bbackup_ajax_handle() function not having a capability check, nor validating user supplied input passed directly to call_user_func(). This makes it possible for unauthenticated attackers to execute code on the server which can be leverage to inject backdoors or create new administrative user accounts to name a few things. On WordPress sites running the Alone theme versions 7.8.4 and older, this can be chained with CVE-2025-5394 to install the Bears Backup plugin and achieve the same impact.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-94: Improper Control of Generation of Code ('Code Injection')
Bears Backup <= 2.0.0 carries this weakness at bbackup_ajax_handle(), and reaching it takes no account at all. Code injection means input from a request reaches a language construct that evaluates code, so the attacker's text is executed rather than treated as data.
The injected code runs with the web server's privileges, giving the attacker the same access to the database and filesystem as WordPress itself. For Bears Backup the fix is 2.1.0: builds <= 2.0.0 are affected, anything from 2.1.0 onward is not.
Remediation
Update to version 2.1.0, or a newer patched version
How does WordSec protect against this?
Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: Bears Backup 2.1.0 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Login Security
External References
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C