The Blocksy theme for WordPress is vulnerable to Stored Cross-Site Scripting via the blocksy_meta metadata fields in all versions up to, and including, 2.1.30 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.
Exploitability
AV:NAC:LPR:LUI:NScope
S:CImpact
C:LI:LA:N6.4/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:NInjection