Cyber Resilience

CVE-2023-6875

CriticalPublic PoC

Published: 11 January 2024

Published
11 January 2024
Modified
08 April 2026
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.9368 99.9th percentile
Risk Priority 76 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-6875 is a critical-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Wpexperts Post Smtp. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 0.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis

The POST SMTP Mailer plugin for WordPress, in all versions through 2.8.7, contains a type-juggling flaw in the connect-app REST endpoint that permits unauthorized data access and modification. The affected component is the mobile REST API handler responsible for API-key authentication and log retrieval.

Unauthenticated attackers can invoke the endpoint to reset the mailer API key and read stored logs that contain password-reset emails, directly enabling full site takeover. The issue is tracked under CWE-639 and CWE-862 and carries a CVSS 3.1 score of 9.8.

Public references point to a patched changeset in the plugin repository and a detailed advisory from Wordfence that describe the authorization bypass; administrators are expected to apply the vendor update that closes the endpoint flaw. CVE-2023-52233 is noted as a duplicate. The associated EPSS score remains elevated near 0.94, and public exploit code has been posted to Packet Storm.

EU & UK References

Vulnerability details

The POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress is vulnerable to unauthorized access of data and modification of data due to a type juggling issue on the connect-app REST…

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endpoint in all versions up to, and including, 2.8.7. This makes it possible for unauthenticated attackers to reset the API key used to authenticate to the mailer and view logs, including password reset emails, allowing site takeover. CVE-2023-52233 appears to be a duplicate of this issue.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

wpexperts
post smtp
≤ 2.8.7

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-862 CWE-639

Requiring a decision for every access request prevents missing authorization checks that would otherwise allow unauthorized access.

addresses: CWE-862 CWE-639

Requiring enforcement of authorizations ensures checks are performed rather than omitted for resources.

addresses: CWE-862

Requiring an access control policy ensures authorization checks are defined and applied for critical functions.

addresses: CWE-862

Reviews of access controls detect missing authorization checks on critical functions or resources.

addresses: CWE-862

Documenting permitted unauthenticated actions prevents missing authorization by making all exceptions explicit and subject to organizational review.

addresses: CWE-862

Requiring attribute association with information prevents authorization from being performed without necessary security or privacy context.

addresses: CWE-862

Mandating authorization prior to allowing remote connections addresses missing authorization for remote access.

addresses: CWE-862

Mandating authorization before wireless connections are allowed prevents missing authorization for wireless access.

References