ConvertPlug <= 3.5.25 - Authenticated (Contributor+) PHP Object Injection
Strategic Overview
- Status
- Patched in 3.5.26
- Affected Plugin
- ConvertPlus
- Affected Version
<= 3.5.25- CVSS
- 8.8High
- Weakness type
- CWE-502 · Deserialization of Untrusted Data
- CVE
CVE-2024-3240
At a glance
CVE-2024-3240 is a high-severity Deserialization of Untrusted Data vulnerability in the ConvertPlus WordPress plugin, affecting versions <= 3.5.25. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 3.5.26; sites on affected versions should update now. Disclosed May 2024, reported by 1337_Wannabe.
Vulnerability Overview
The ConvertPlug plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.5.25 via deserialization of untrusted input from the 'settings_encoded' attribute of the 'smile_info_bar' shortcode. This makes it possible for authenticated attackers, with contributor-level access and above, to inject a PHP Object. No POP chain is present in the vulnerable plugin. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.
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 interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-502: Deserialization of Untrusted Data
ConvertPlus <= 3.5.25 carries this weakness at settings_encoded, and reaching it takes an account at Contributor level or above. Deserialization of untrusted data means the application reconstructs objects from input a caller controls, letting the attacker choose which classes get instantiated and what their properties hold.
A workable chain turns deserialization into file writes, deletions or code execution, depending on what the loaded classes do in their magic methods. For ConvertPlus the fix is 3.5.26: builds <= 3.5.25 are affected, anything from 3.5.26 onward is not.
Remediation
Update to version 3.5.26, or a newer patched version
How does WordSec protect against this?
An attacker needs Contributor access first, so the firewall sees the attempt as traffic from a logged-in account: 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: ConvertPlus 3.5.26 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Alerts
External References
Related records
Same weakness class
Other vulnerabilities in ConvertPlus
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