The LDAP directory connector in Atlassian Crowd before 2.8.8 and 2.9.x before 2.9.5 allows remote attackers to execute arbitrary code via an LDAP attribute with a crafted serialized Java object, aka LDAP entry poisoning.
https://jira.atlassian.com/browse/CWD-4790
https://confluence.atlassian.com/crowd/crowd-security-advisory-2016-10-19-856697283.html
http://www.securityfocus.com/bid/93826
http://www.securityfocus.com/archive/1/539655/100/0/threaded