RULE(RULE ID:320638)

Rule General Information
Release Date: 2017-12-12
Rule Name: DB-OTHER Apache CouchDB JSON Remote Privilege Escalation Vulnerability - 4 (CVE-2017-12635)
Severity:
CVE ID:
Rule Protection Details
Description: 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.
Impact: An attacker can abtain more privileges which he is not entitled to by exloiting the vulnerability, such as executing arbitrary code, deleting files, viewing sensitive information, changing configurations.
Affected OS: Windows, Linux, FreeBSD, Solaris, Other Unix, Network Device, Mac OS, iOS, Android, Others
Reference: SecurityFocusBID:101868
https://lists.apache.org/thread.html/6c405bf3f8358e6314076be9f48c89a2e0ddf00539906291ebdf0c67@%3Cdev.couchdb.apache.org%3E
https://security.gentoo.org/glsa/201711-16
Solutions
Upgrade to version 1.7.0 or 2.1.1 to solve the problem.