My Calendar WordPress plugin 3.8.8 before 3.8.11 contains a shortcode injection vulnerability that…

Why it is Yellow

• CVSS 6.5 medium

References

• https://github.com/joedolson/my-calendar
• https://github.com/joedolson/my-calendar/blob/v3.8.10/src/my-calendar-search.php#L170
• https://github.com/joedolson/my-calendar/commit/de875c25d9651abb041b2dfe32f60a4320c66496
• https://github.com/joedolson/my-calendar/releases/tag/v3.8.11
• https://www.vulncheck.com/advisories/my-calendar-3.8.8-before-3.8.11-unauthenticated-shortcode-injection-via-mcs-parameter

Original description

My Calendar WordPress plugin 3.8.8 before 3.8.11 contains a shortcode injection vulnerability that allows unauthenticated attackers to execute registered shortcodes via the mcs search parameter. The mcs value reaches mc_search_results() in src/my-calendar-search.php without bracket encoding before do_shortcode runs, so a GET request triggers shortcodes on any page or post, enabling content injection and spoofing.