This is a very serious remote exploitation of the Crowd service, looks like version 2.6.3 is the only fully patched and safe version. Abstract: This advisory

This is a very serious remote exploitation of the Crowd service, looks like version 2.6.3 is the only fully patched and safe version. Abstract: This advisory examines a critical vulnerability in Atlassian Crowd a software package marketed as a turnkey solution for enterprise scale single sign­on and secure user authentication. The vulnerability is remotely accessible, does not require authentication, and is easily exploited. Recommendations for securing affected systems are provided and special mention is made of an unpatched weakness in the product that could be classified as a symmetric backdoor.