CVE-2023-6187
Published: 18 November 2023
Summary
CVE-2023-6187 is a high-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Strangerstudios Paid Memberships Pro. Its CVSS base score is 7.5 (High).
Operationally, ranked in the top 4.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
The Paid Memberships Pro plugin for WordPress is vulnerable to arbitrary file uploads in versions up to and including 2.12.3. The flaw stems from insufficient file type validation in the pmpro_paypalexpress_session_vars_for_user_fields function within fields.php, which permits upload of arbitrary files when specific payment gateways and custom user field visibility settings are in use.
Authenticated attackers holding subscriber-level privileges or higher can exploit the issue when either the deprecated 2Checkout gateway or PayPal Express is configured as the payment method and a custom user field is restricted to profile visibility only. Successful exploitation allows upload of malicious files to the server, which may enable remote code execution and full site compromise under the CVSS 7.5 rating.
The vendor addressed the vulnerability in version 2.12.4 through changesets that update file handling logic in fields.php and functions.php. Site administrators are advised to upgrade immediately, and Wordfence and the Paid Memberships Pro advisory both recommend verifying payment gateway settings and reviewing any custom profile-only fields as interim steps.
EPSS scores have remained essentially flat near 0.20 since disclosure, indicating no significant surge in observed exploitation interest.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-58436
Vulnerability details
The Paid Memberships Pro plugin for WordPress is vulnerable to arbitrary file uploads due to insufficient file type validation in the 'pmpro_paypalexpress_session_vars_for_user_fields' function in versions up to, and including, 2.12.3. This makes it possible for authenticated attackers with subscriber privileges…
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or above, to upload arbitrary files on the affected site's server which may make remote code execution possible. This can be exploited if 2Checkout (deprecated since version 2.6) or PayPal Express is set as the payment method and a custom user field is added that is only visible at profile, and not visible at checkout according to its settings.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
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.
Requiring identifiable owners for portable devices reduces the attack surface for unrestricted uploads of dangerous file types via anonymous media.
Dangerous file uploads can be detonated in the chamber to determine malice before any production write or execution occurs.
Prevents unrestricted writing of arbitrary or malicious firmware by keeping hardware write-protect enabled except under tightly controlled manual procedures.
Scans files from external sources on download/open/execute, blocking unrestricted uploads of dangerous file types.