The My Calendar – Accessible Event Manager WordPress plugin versions up to 3.8.7 contain a critical privilege escalation vulnerability. An unauthenticated attacker can inject a crafted shortcode via the public 'mcs' GET parameter, leading to arbitrary PHP function calls. This flaw allows overwriting the Administrator account credentials (user ID 1), granting full administrative access. The vulnerability is exploitable through the plugin's publicly accessible /my-calendar/ page by default upon activation.
The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'before' and 'after' Shortcode Attributes 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 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.
The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to time-based blind SQL Injection via the 'mc_auth' parameter in all versions up to, and including, 3.7.8 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.
The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 3.7.14 via the 'vcal' parameter due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to enumerate occurrence IDs and access the full iCalendar export of non-public, draft, trashed, and personal calendar events, disclosing sensitive event metadata including titles, descriptions, dates, locations, organizer and host details, permalinks, and related calendar metadata.
The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 3.7.9. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with custom-level access and above, to bypass the moderation and approval workflow by tampering with the POST body to publish events or set other unauthorized statuses such as cancelled or private, in ways their role does not permit. While the UI correctly restricts low-privilege users to a draft-only submit button, this restriction is enforced only client-side, making it trivially bypassable by directly manipulating the POST request.
A vulnerability in the My Calendar WordPress plugin (versions 3.7.6 and below) allows unauthenticated attackers to exploit an AJAX endpoint that improperly parses user-supplied parameters. On WordPress Multisite installations, this enables unauthorized access to calendar events from any sub-site by switching to arbitrary site IDs. On single-site installations, the flaw causes a PHP fatal error leading to denial of service. The issue is fixed in version 3.7.7.
The My Calendar – Accessible Event Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `template` attribute of the `[my_calendar_upcoming]` shortcode in all versions up to, and including, 3.7.3. This is due to the use of `stripcslashes()` on user-supplied shortcode attribute values in the `mc_draw_template()` function, which decodes C-style hex escape sequences (e.g., `\x3c` to `<`) at render time, bypassing WordPress's `wp_kses_post()` content sanitization that runs at save time. 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 WP Accessibility plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via the 'alt' attribute of images processed by the "Long Description UI" feature in all versions up to, and including, 2.3.1. This is due to the plugin's JavaScript retrieving the alt attribute using getAttribute() and unsafely concatenating it into innerHTML and insertAdjacentHTML calls without proper sanitization or 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. Exploitation requires the "Long Description UI" setting to be enabled and set to "Link to description."