Think you have a false positive on this rule?

Sid 1-44890

Message

SERVER-OTHER Apache CouchDB remote privilege escalation attempt

Summary

This event is generated when an attacker attempts to create an admin user in CouchDB.

Impact

Remote code execution and potential user-access to the server.

CVE-2017-12635:

CVSS base score 9.8

CVSS impact score 5.9

CVSS exploitability score 3.9

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Detailed information

CVE-2017-12635: Due to differences in the Erlang-based JSON parser and JavaScript-based JSON parser, it is possible in Apache CouchDB before 1.7.0 and 2.x before 2.1.1 to submit users documents with duplicate keys for 'roles' used for access control within the database, including the special case 'admin' role, that denotes administrative users. In combination with CVE-2017-12636 (Remote Code Execution), this can be used to give non-admin users access to arbitrary shell commands on the server as the database system user. The JSON parser differences result in behaviour that if two 'roles' keys are available in the JSON, the second one will be used for authorising the document write, but the first 'roles' key is used for subsequent authorization for the newly created user. By design, users can not assign themselves roles. The vulnerability allows non-admin users to give themselves admin privileges.

Affected systems

  • apache couchdb 1.0.0
  • apache couchdb 1.0.1
  • apache couchdb 1.0.2
  • apache couchdb 1.0.3
  • apache couchdb 1.0.4
  • apache couchdb 1.1.0
  • apache couchdb 1.1.1
  • apache couchdb 1.1.2
  • apache couchdb 1.2.0
  • apache couchdb 1.2.1
  • apache couchdb 1.5.0
  • apache couchdb 2.0.0

Ease of attack

CVE-2017-12635:

Access Vector

Access Complexity

Authentication

False positives

False negatives

Corrective action

Upgrade to CouchDB versions 1.7.1 or 2.1.1.

Contributors

  • Cisco's Talos Intelligence Group

Additional References