POST SMTP Mailer <= 2.5.6 - Cross-Site Request Forgery to Account Compromise
Strategic Overview
- Status
- Patched in 2.5.7
- Affected Plugin
- Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App
- Affected Version
<= 2.5.6- CVSS
- 6.5Medium
- Weakness type
- CWE-352 · Cross-Site Request Forgery (CSRF)
- CVE
CVE-2023-3179
At a glance
CVE-2023-3179 is a medium-severity Cross-Site Request Forgery (CSRF) vulnerability in the Post SMTP WordPress plugin, affecting versions <= 2.5.6. It carries a CVSS score of 6.5 (reachable over the network; low attack complexity; high confidentiality impact). Exploitation requires no authentication. The issue is fixed in version 2.5.7; sites on affected versions should update now. Disclosed June 2023, reported by Erwan LR.
Vulnerability Overview
The POST SMTP Mailer plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.5.6. This is due to incorrect nonce validation on the resend_email() function. This makes it possible for unauthenticated attackers to resend emails to an arbitrary email address via a forged request granted they can trick a site user with the manage_postman_smtp capability into performing an action such as clicking on a link. An attacker could leverage this to resend a password reset email to their own account and compromise a site administrators account.
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.
CWE-352: Cross-Site Request Forgery (CSRF)
Post SMTP <= 2.5.6 carries this weakness at resend_email(), 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 Post SMTP the fix is 2.5.7: builds <= 2.5.6 are affected, anything from 2.5.7 onward is not.
Remediation
Update to version 2.5.7, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to Post SMTP: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Post SMTP 2.5.7 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Same weakness class
Other vulnerabilities in Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App
- 9.8CVE-2025-11833: Post SMTP Account Takeover
CVE-2025-11833 - 9.8CVE-2023-6875: POST SMTP Mailer Authorization Bypass
CVE-2023-6875 - 8.8CVE-2025-24000: Post SMTP Authenticated (Subscriber+) Account Takeover
CVE-2025-24000 - 7.2CVE-2026-48838: Post SMTP Stored XSS
CVE-2026-48838 - 7.2CVE-2026-3090: Post SMTP <= 3.8.0 Stored Cross-Site Scripting
CVE-2026-3090 - 7.2CVE-2025-0521: Post SMTP <= 3.0.2 Stored Cross-Site Scripting
CVE-2025-0521 - 7.2CVE-2024-5207: POST SMTP Mailer SQL Injection
CVE-2024-5207 - 7.2CVE-2023-7027: POST SMTP Mailer Stored XSS
CVE-2023-7027
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C