JasperServer in JasperReports Server Community Project 3.7.0 and 3.7.1 uses a predictable _flowExecutionKey parameter, which makes it easier for remote attackers to conduct cross-site request forgery (CSRF) attacks via a brute-force approach.
www.csirtcv.gva.es/es/alertas/vulnerabilidad-en-jasperserver.html
www.csirtcv.gva.es/sites/all/files/images/content/%5BCSIRT-cv%5D%20JasperServer%203.7.0%20CE%20CSRF%20Advisory.pdf
www.kb.cert.org/vuls/id/519588
www.kb.cert.org/vuls/id/MAPG-8ELLJC
www.securityfocus.com/bid/49649
exchange.xforce.ibmcloud.com/vulnerabilities/69849