Unspecified vulnerability in Sonatype Nexus OSS and Pro 2.4.0 through 2.7.1 allows attackers to create arbitrary user accounts via unknown vectors related to "an unauthenticated execution path."
https://support.sonatype.com/entries/42374566-CVE-2014-2034-Nexus-Security-Advisory-REST-API
http://www.sonatype.org/advisories/archive/2014-03-03-Nexus