Vulnerabilities > CVE-2020-1955 - Missing Authentication for Critical Function vulnerability in Apache Couchdb 3.0.0
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
HIGH Integrity impact
HIGH Availability impact
HIGH Summary
CouchDB version 3.0.0 shipped with a new configuration setting that governs access control to the entire database server called `require_valid_user_except_for_up`. It was meant as an extension to the long standing setting `require_valid_user`, which in turn requires that any and all requests to CouchDB will have to be made with valid credentials, effectively forbidding any anonymous requests. The new `require_valid_user_except_for_up` is an off-by-default setting that was meant to allow requiring valid credentials for all endpoints except for the `/_up` endpoint. However, the implementation of this made an error that lead to not enforcing credentials on any endpoint, when enabled. CouchDB versions 3.0.1[1] and 3.1.0[2] fix this issue.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 1 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Choosing a Message/Channel Identifier on a Public/Multicast Channel Attackers aware that more data is being fed into a multicast or public information distribution means can 'select' information bound only for another client, even if the distribution means itself forces users to authenticate in order to connect initially. Doing so allows the attacker to gain access to possibly privileged information, possibly perpetrate other attacks through the distribution means by impersonation. If the channel/message being manipulated is an input rather than output mechanism for the system, (such as a command bus), this style of attack could change its identifier from a less privileged to more so privileged channel or command.
- Using Unpublished Web Service APIs An attacker searches for and invokes Web Services APIs that the target system designers did not intend to be publicly available. If these APIs fail to authenticate requests the attacker may be able to invoke services and/or gain privileges they are not authorized for.
- Manipulating Writeable Terminal Devices This attack exploits terminal devices that allow themselves to be written to by other users. The attacker sends command strings to the target terminal device hoping that the target user will hit enter and thereby execute the malicious command with their privileges. The attacker can send the results (such as copying /etc/passwd) to a known directory and collect once the attack has succeeded.
- Cross Site Request Forgery (aka Session Riding) An attacker crafts malicious web links and distributes them (via web pages, email, etc.), typically in a targeted manner, hoping to induce users to click on the link and execute the malicious action against some third-party application. If successful, the action embedded in the malicious link will be processed and accepted by the targeted application with the users' privilege level. This type of attack leverages the persistence and implicit trust placed in user session cookies by many web applications today. In such an architecture, once the user authenticates to an application and a session cookie is created on the user's system, all following transactions for that session are authenticated using that cookie including potential actions initiated by an attacker and simply "riding" the existing session cookie.
Nessus
| NASL family | Databases |
| NASL id | COUCHDB_3_1_0.NASL |
| description | According to its banner, the version of CouchDB running on the remote host is 3.x prior to 3.0.1. It is, therefore, potentially affected by a privilege escalation which could allow users to access endpoints which should require authentication. Note that Nessus did not actually test for these flaws but instead, has relied on the version in CouchDB |
| last seen | 2020-06-06 |
| modified | 2020-05-28 |
| plugin id | 136945 |
| published | 2020-05-28 |
| reporter | This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/136945 |
| title | Apache CouchDB 3.x < 3.0.1 Privilege Escalation |