Strategic Overview
- Status
- Unpatched
- Affected Plugin
- Newsletter Manager
- Affected Version
<= 1.5.1- CVSS
- 9.8Critical
- Weakness type
- CWE-502 · Deserialization of Untrusted Data
- CVE
CVE-2020-36727
At a glance
CVE-2020-36727 is a critical-severity Deserialization of Untrusted Data vulnerability in the Newsletter Manager WordPress plugin, affecting versions <= 1.5.1. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed December 2020, reported by Jerome Bruandet.
Vulnerability Overview
The Newsletter Manager plugin for WordPress is vulnerable to insecure deserialization in versions up to, and including, 1.5.1. This is due to unsanitized input from the 'customFieldsDetails' parameter being passed through a deserialization function. This potentially makes it possible for unauthenticated attackers to inject a serialized PHP object.
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-502: Deserialization of Untrusted Data
Newsletter Manager <= 1.5.1 carries this weakness at customFieldsDetails, and reaching it takes a caller who can reach the endpoint. 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. No fixed build of this plugin is recorded for Newsletter Manager yet, so installs running <= 1.5.1 stay exposed until the vendor ships one.
Remediation
No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.
How does WordSec protect against this?
The attempt arrives as an ordinary request to Newsletter Manager: 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. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.
- Firewall
- Scanner
- Alerts
External References
Related records
Other vulnerabilities in Newsletter Manager
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