This indicates an attack attempt to exploit an Elevation of Privilege vulnerability in Apache CouchDB.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted HTTP request. A remote attacker may be able to exploit this to elevate their privileges, via a crafted HTTP request.
Apache Software Foundation CouchDB prior to 2.1.1
Apache Software Foundation CouchDB prior to 1.7
Privilege Escalation: Remote attackers can leverage their privileges on vulnerable systems.
Apply the most recent upgrade or patch from the vendor.