CVE-2025-13516: brainstormforce suremail – smtp and email logs plugin with amazon ses, postmark, and other providers

Vulnerability summary

CVE-2025-13516 is a high (CVSS 8.1) vulnerability in brainstormforce suremail – smtp and email logs plugin with amazon ses, postmark, and other providers. EPSS estimates a 0.97% chance of exploitation in the next 30 days, higher than 61% of scored vulnerabilities. Fixed in 1.9.1.

Timeline

1. 02-12-2025
   PublishedVulnerability first disclosed.
2. 08-04-2026
   Last modifiedVulnerability information updated.

Description

The SureMail – SMTP and Email Logs Plugin for WordPress is vulnerable to Unrestricted Upload of File with Dangerous Type in versions up to and including 1.9.0. This is due to the plugin's save_file() function in inc/emails/handler/uploads.php which duplicates all email attachments to a web-accessible directory (wp-content/uploads/suremails/attachments/) without validating file extensions or content types. Files are saved with predictable names derived from MD5 hashes of their content. While the plugin attempts to protect this directory with an Apache .htaccess file to disable PHP execution, this protection is ineffective on nginx, IIS, and Lighttpd servers, or on misconfigured Apache installations. This makes it possible for unauthenticated attackers to achieve Remote Code Execution by uploading malicious PHP files through any public form that emails attachments, calculating the predictable filename, and directly accessing the file to execute arbitrary code granted they are exploiting a site running on an affected web server configuration.

• CWE-434Unrestricted Upload of File with Dangerous TypeThe product allows the upload or transfer of dangerous file types that are automatically processed within its environment.