v5/config/system.php in dayrui FineCms 5.2.0 has a default SYS_KEY value and does not require key regeneration for each installation, which allows remote attackers to upload arbitrary .php files via a member api swfupload action to index.php.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.007
EPSS Ranking 71.3%