Schedule Posts Calendar <= 5.2 - Cross-Site Request Forgery
Strategic Overview
- Status
- Patched in 5.3
- Affected Plugin
- Schedule Posts Calendar
- Affected Version
<= 5.2- CVSS
- 4.3Medium
- Weakness type
- CWE-352 · Cross-Site Request Forgery (CSRF)
- CVE
CVE-2023-40556
At a glance
CVE-2023-40556 is a medium-severity Cross-Site Request Forgery (CSRF) vulnerability in the Schedule Posts Calendar WordPress plugin, affecting versions <= 5.2. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 5.3; sites on affected versions should update now. Disclosed August 2023, reported by Nguyen Xuan Chien.
Vulnerability Overview
The Schedule Posts Calendar plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 5.2. This is due to missing nonce validation on the schedule_posts_calendar_admin_page() function. This makes it possible for unauthenticated attackers to modify the plugin's settings 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.
CWE-352: Cross-Site Request Forgery (CSRF)
Schedule Posts Calendar <= 5.2 carries this weakness at schedule_posts_calendar_admin_page(), and reaching it 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 Schedule Posts Calendar the fix is 5.3: builds <= 5.2 are affected, anything from 5.3 onward is not.
Remediation
Update to version 5.3, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to Schedule Posts Calendar: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Schedule Posts Calendar 5.3 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Other vulnerabilities in Schedule Posts Calendar
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