CVE-2017-12635 Privilege escalation in Apache CouchDB
Non-admin users can escalate to admin privileges by exploiting JSON parser differences in Apache CouchDB, potentially leading to full system compromise.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2017-12635?
CVE-2017-12635 is a critical vulnerability in Apache CouchDB, published on 14 Nov 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-269
Which versions are affected by CVE-2017-12635?
It affects 1 product.
Products include Apache Couchdb.
How do I fix CVE-2017-12635?
Upgrade to a fixed version.
Is CVE-2017-12635 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2017-12635 exists.
Public exploit code: 2 Metasploit modules, 3 Exploit-DB entries, 1 Nuclei template and 5 proofs of concept on GitHub.
Other vulnerabilities in Apache CouchDB
Sources
Also known as GHSA-f3p2-qqmm-jg8f, UBUNTU-CVE-2017-12635.