ID CVE-2017-12635
Summary 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.
References
Vulnerable Configurations
  • Apache Software Foundation CouchDB 1.0.0
    cpe:2.3:a:apache:couchdb:1.0.0
  • Apache Software Foundation CouchDB 1.0.1
    cpe:2.3:a:apache:couchdb:1.0.1
  • Apache Software Foundation CouchDB 1.0.2
    cpe:2.3:a:apache:couchdb:1.0.2
  • Apache Software Foundation CouchDB 1.0.3
    cpe:2.3:a:apache:couchdb:1.0.3
  • Apache Software Foundation CouchDB 1.0.4
    cpe:2.3:a:apache:couchdb:1.0.4
  • Apache Software Foundation CouchDB 1.1.0
    cpe:2.3:a:apache:couchdb:1.1.0
  • Apache Software Foundation CouchDB 1.1.1
    cpe:2.3:a:apache:couchdb:1.1.1
  • Apache Software Foundation CouchDB 1.1.2
    cpe:2.3:a:apache:couchdb:1.1.2
  • Apache Software Foundation CouchDB 1.2.0
    cpe:2.3:a:apache:couchdb:1.2.0
  • Apache Software Foundation CouchDB 1.2.1
    cpe:2.3:a:apache:couchdb:1.2.1
  • Apache Software Foundation CouchDB 1.5.0
    cpe:2.3:a:apache:couchdb:1.5.0
  • Apache Software Foundation CouchDB 2.0.0
    cpe:2.3:a:apache:couchdb:2.0.0
  • cpe:2.3:a:apache:couchdb:2.0.0:rc1
    cpe:2.3:a:apache:couchdb:2.0.0:rc1
  • cpe:2.3:a:apache:couchdb:2.0.0:rc2
    cpe:2.3:a:apache:couchdb:2.0.0:rc2
  • cpe:2.3:a:apache:couchdb:2.0.0:rc3
    cpe:2.3:a:apache:couchdb:2.0.0:rc3
  • cpe:2.3:a:apache:couchdb:2.0.0:rc4
    cpe:2.3:a:apache:couchdb:2.0.0:rc4
CVSS
Base: 10.0
Impact:
Exploitability:
CWE CWE-264
CAPEC
  • Accessing, Modifying or Executing Executable Files
    An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Blue Boxing
    This type of attack against older telephone switches and trunks has been around for decades. A tone is sent by an adversary to impersonate a supervisor signal which has the effect of rerouting or usurping command of the line. While the US infrastructure proper may not contain widespread vulnerabilities to this type of attack, many companies are connected globally through call centers and business process outsourcing. These international systems may be operated in countries which have not upgraded Telco infrastructure and so are vulnerable to Blue boxing. Blue boxing is a result of failure on the part of the system to enforce strong authorization for administrative functions. While the infrastructure is different than standard current applications like web applications, there are historical lessons to be learned to upgrade the access control for administrative functions.
  • Restful Privilege Elevation
    Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.
  • Target Programs with Elevated Privileges
    This attack targets programs running with elevated privileges. The attacker would try to leverage a bug in the running program and get arbitrary code to execute with elevated privileges. For instance an attacker would look for programs that write to the system directories or registry keys (such as HKLM, which stores a number of critical Windows environment variables). These programs are typically running with elevated privileges and have usually not been designed with security in mind. Such programs are excellent exploit targets because they yield lots of power when they break. The malicious user try to execute its code at the same level as a privileged system call.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.
exploit-db via4
  • description Apache CouchDB 1.7.0 and 2.x before 2.1.1 - Remote Privilege Escalation. CVE-2017-12635. Webapps exploit for Linux platform
    file exploits/linux/webapps/44498.py
    id EDB-ID:44498
    last seen 2018-05-24
    modified 2018-04-23
    platform linux
    port
    published 2018-04-23
    reporter Exploit-DB
    source https://www.exploit-db.com/download/44498/
    title Apache CouchDB 1.7.0 and 2.x before 2.1.1 - Remote Privilege Escalation
    type webapps
  • description Apache CouchDB < 2.1.0 - Remote Code Execution. CVE-2017-12636. Webapps exploit for Linux platform
    file exploits/linux/webapps/44913.py
    id EDB-ID:44913
    last seen 2018-06-20
    modified 2018-06-20
    platform linux
    port
    published 2018-06-20
    reporter Exploit-DB
    source https://www.exploit-db.com/download/44913/
    title Apache CouchDB < 2.1.0 - Remote Code Execution
    type webapps
  • description Apache CouchDB - Arbitrary Command Execution (Metasploit). CVE-2017-12635,CVE-2017-12636. Remote exploit for Linux platform. Tags: Metasploit Framework (MSF)...
    file exploits/linux/remote/45019.rb
    id EDB-ID:45019
    last seen 2018-07-13
    modified 2018-07-13
    platform linux
    port 5984
    published 2018-07-13
    reporter Exploit-DB
    source https://www.exploit-db.com/download/45019/
    title Apache CouchDB - Arbitrary Command Execution (Metasploit)
    type remote
metasploit via4
nessus via4
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2017-A20D92573B.NASL
    description - CouchDB ver. 1.7.1 - Fixed CVE-2017-12635 - Fixed CVE-2017-12636 - Switched to eunit for testing - Erlang 20 compatible Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-07-16
    plugin id 105943
    published 2018-01-15
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=105943
    title Fedora 27 : couchdb / erlang-jiffy (2017-a20d92573b)
  • NASL family Gentoo Local Security Checks
    NASL id GENTOO_GLSA-201711-16.NASL
    description The remote host is affected by the vulnerability described in GLSA-201711-16 (CouchDB: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in CouchDB. Please review the CVE identifiers referenced below for details. Impact : A remote attacker could execute arbitrary shell commands or escalate privileges. Workaround : There is no known workaround at this time.
    last seen 2019-02-21
    modified 2018-07-13
    plugin id 104697
    published 2017-11-20
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=104697
    title GLSA-201711-16 : CouchDB: Multiple vulnerabilities
  • NASL family FreeBSD Local Security Checks
    NASL id FREEBSD_PKG_1E54D140849311E8A7950028F8D09152.NASL
    description Apache CouchDB PMC reports : Database Administrator could achieve privilege escalation to the account that CouchDB runs under, by abusing insufficient validation in the HTTP API, escaping security controls implemented in previous releases.
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 111018
    published 2018-07-12
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=111018
    title FreeBSD : couchdb -- multiple vulnerabilities (1e54d140-8493-11e8-a795-0028f8d09152)
  • NASL family Debian Local Security Checks
    NASL id DEBIAN_DLA-1252.NASL
    description CVE-2017-12635 Prevent non-admin users to give themselves admin privileges. CVE-2017-12636 Blacklist some configuration options to prevent execution of arbitrary shell commands as the CouchDB user For Debian 7 'Wheezy', these problems have been fixed in version 1.2.0-5+deb7u1. We recommend that you upgrade your couchdb packages. NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-07-13
    plugin id 106208
    published 2018-01-22
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=106208
    title Debian DLA-1252-1 : couchdb security update
packetstorm via4
refmap via4
bid 101868
gentoo GLSA-201711-16
mlist
  • [debian-lts-announce] 20180121 [SECURITY] [DLA 1252-1] couchdb security update
  • [dev] 20171114 Apache CouchDB CVE-2017-12635 and CVE-2017-12636
Last major update 14-11-2017 - 15:29
Published 14-11-2017 - 15:29
Last modified 27-07-2018 - 21:29
Back to Top