WordPress CVEs

Description

The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'fallback' Shortcode Attribute in all versions up to, and including, 3.8.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The bypass relies on hex-encoded shortcode attribute payloads (e.g. \x3cscript\x3e), which wp_kses_post cannot strip on save because they appear as literal backslash sequences rather than real HTML tags; WordPress core's shortcode_parse_atts() then calls stripcslashes() at render time, decoding the escapes into real angle brackets before they reach the unescaped sink.

Affected WordPress components

• My Calendar – Accessible Event Manager Plugin · my-calendar
  Confirmed match Active
  Up to and including 3.8.3
  View on WordPress.org

A confirmed match is backed by the plugin or theme slug. A possible match is based on the product name only and should be verified.

Affected products and versions

• joedolson My Calendar – Accessible Event Manager — Up to and including 3.8.3

References

• github.com https://github.com/joedolson/my-calendar/commit/89bbf7314fac84cdb89e520e8b7b6d69eee8dd3c
• plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/my-calendar/trunk/my-calendar-shortcodes.php#L114
• plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/my-calendar/trunk/my-calendar-widgets.php#L272
• plugins.trac.wordpress.org https://plugins.trac.wordpress.org/browser/my-calendar/trunk/my-calendar.php#L556
• www.wordfence.com https://www.wordfence.com/threat-intel/vulnerabilities/id/62c8fb1f-6cba-43cc-8aca-70812c29a63d?source=cve
• nvd.nist.gov Official NVD record