Post Index <= 0.7.5 Cross-Site Request Forgery to Stored Cross-Site Scripting
Strategic Overview
- Status
- Unpatched
- Affected Plugin
- Post Index
- Affected Version
<= 0.7.5- CVSS
- 8.8High
- Weakness type
- CWE-352 · Cross-Site Request Forgery (CSRF)
- CVE
CVE-2021-34637
At a glance
CVE-2021-34637 is a high-severity Cross-Site Request Forgery (CSRF) vulnerability in the Post Index WordPress plugin, affecting versions <= 0.7.5. It carries a CVSS score of 8.8 (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 July 2021, reported by Kentaro Kuroki, Cryptography Laboratory in Tokyo Denki University.
Vulnerability Overview
The Post Index WordPress plugin is vulnerable to Cross-Site Request Forgery via the OptionsPage function found in the ~/php/settings.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 0.7.5.
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 Post Index <= 0.7.5 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. No fixed build of this plugin is recorded for Post Index yet, so installs running <= 0.7.5 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 Post Index: WordSec's web application firewall inspects request payloads before WordPress loads 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
- Alerts
External References
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C