Strategic Overview
- Status
- Patched in 4.6.1
- Affected Plugin
- EELV Newsletter
- Affected Version
<= 4.6.0- CVSS
- 8.8High
- Weakness type
- CWE-352 · Cross-Site Request Forgery (CSRF)
- CVE
CVE-2017-18523
At a glance
CVE-2017-18523 is a high-severity Cross-Site Request Forgery (CSRF) vulnerability in the EELV Newsletter WordPress plugin, affecting versions <= 4.6.0. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 4.6.1; sites on affected versions should update now. Disclosed May 2017.
Vulnerability Overview
The EELV Newsletter plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 4.6.0. This is due to missing or incorrect nonce validation in the 'eelv-newsletter/trunk/lettreinfo.php' file. This makes it possible for unauthenticated attackers to gain otherwise restricted access to administrative actions via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
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. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-352: Cross-Site Request Forgery (CSRF)
Reaching this weakness in EELV Newsletter <= 4.6.0 takes a caller who can reach the endpoint. Cross-site request forgery abuses the fact that browsers attach a victim's cookies to any request, so a state-changing action that only checks who you are, not whether you meant to act, can be triggered from another site.
An attacker who gets a logged-in user to load a crafted page can perform that action as them, with the impact scaling to whatever the victim's role is allowed to do. For EELV Newsletter the fix is 4.6.1: builds <= 4.6.0 are affected, anything from 4.6.1 onward is not.
Remediation
Update to version 4.6.1, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to EELV Newsletter: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: EELV Newsletter 4.6.1 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Same weakness class
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