Divi Form Builder <= 5.1.8 - Unauthenticated Arbitrary File Upload Leading to Remote Code Execution via 'acceptFileTypes' Parameter
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- 1 proof of concept on GitHub, 1 Nuclei template
- Exploitation: none
- Automatable: yes
- Technical impact: total
Summary
The Divi Form Builder plugin for WordPress is vulnerable to Arbitrary File Upload leading to Remote Code Execution in all versions up to and including 5.1.8. This is due to insufficient file extension validation in the do_image_upload() function where user-supplied input from the acceptFileTypes POST parameter is directly interpolated into a regular expression used to validate uploaded files. Attackers can specify PHP-executable extensions such as .phtml, .phar, .php5, or .php7 to bypass the plugin's .htaccess protection which only blocks .php files specifically. Additionally, on Nginx-based servers, the .htaccess protection is completely ineffective as Nginx does not process .htaccess files. This makes it possible for unauthenticated attackers (who can obtain a nonce from any public page containing a form) to upload executable PHP files to the publicly accessible /wp-content/uploads/de_fb_uploads/ directory and achieve Remote Code Execution by accessing the uploaded file via HTTP. The vulnerability was partially patched in version 5.1.3.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: total
- Record last updated
Affected versions
- Divi Engine Divi Form Builder
through 5.1.8