#VU17274 Permissions, Privileges, and Access Controls in CouchDB - CVE-2017-12635

Vulnerability identifier: #VU17274

Vulnerability risk: Low

CVSSv4.0: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:A/U:Clear]

CVE-ID: CVE-2017-12635

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
CouchDB
Server applications / Database software

Vendor: Apache Foundation

Description

The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due differences in the Erlang-based JSON parser and JavaScript-based JSON parser that can lead to submitting "_users" documents with duplicate keys for "roles" used for access control within the database, including the "_admin" role. A remote authenticated user can create a specially crafted document and abuse the JSON parser differences result in behavior for two 'roles' keys within a single document and gain administrative privileges within the database.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

CouchDB: 1.1.0 - 2.1.0

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External links
https://www.securityfocus.com/bid/101868
https://lists.apache.org/thread.html/6c405bf3f8358e6314076be9f48c89a2e0ddf00539906291ebdf0c67@%3Cdev.couchdb.apache.org%3E
https://lists.debian.org/debian-lts-announce/2018/01/msg00026.html
https://security.gentoo.org/glsa/201711-16
https://www.exploit-db.com/exploits/44498/
https://www.exploit-db.com/exploits/45019/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.