Splunk 4.3.3 – Arbitrary File Read
# Exploit Title: Splunk <= 4.3.3 Reading Arbitrary Files Contents # Date: 09/03/2012 # Exploit Author: Marcio Almeida (marcio.macedo@ciphersec.com.br) # Vendor Homepage: http://www.splunk.com/ # Software Link: http://www.splunk.com/download?r=header # Version: 4.3.3 and priors # Tested on: Linux ================================================================= - Release date: September 3rd, 2012 - Discovered by: Marcio Almeida of CIPHER Intelligence Labs - Severity: Medium - CVSS Base Score: 6.3 (AV:N/AC:M/Au:S/C:C/I:N/A:N/E:P/RL:U/RC:C) ================================================================= I. VULNERABILITY ------------------------- Splunk <= 4.3.3 Reading Arbitrary Files Contents II. BACKGROUND ------------------------- Splunk[1][2][3] is a software to search, monitor and analyze machine-generated data by applications, systems and IT infrastructure at scale via a web-style interface.[4] Splunk captures, indexes and correlates real-time data in a searchable repository from which it can generate graphs, reports, alerts, dashboards and visualizations.[5][6] Splunk aims to make machine data accessible across an organization and identifies data patterns[7], provides metrics, diagnoses problems and provides intelligence for business operation. Splunk is a horizontal technology used for application management, security and compliance, as well as business and web analytics.[8] Splunk has over 3,700 licensed customers in 74 countries, including almost half of the Fortune 100.[9] III. INTRODUCTION ------------------------- Splunk 4.3.3 and prior versions has "Data Preview" functionality located at: "Manager >> Data Inputs >> Files & Directories >> Data Preview" which allows an authenticated user to read the content of arbitrary files on the server it is running. IV. PROOF OF CONCEPT ------------------------- 1 - Go to the screen of functionality located at "Manager >> Data Inputs >> Files & Directories >> Data Preview". 2 - Insert the path to file into "Path to file on server" field. 3 - Click on Continue. 4 - See the content of file. The following screenshots illustrate reading the contents of /etc/shadow: Step 1: http://imageshack.us/f/837/etcshadowserversplunk0d.png/ Step 2: http://imageshack.us/f/835/etcshadowserversplunk0d.png/ V. BUSINESS IMPACT ------------------------- An authenticated attacker with admin privileges on splunk could exploit the vulnerability to retrieve the contents of any sensitive files in the server accessible by the operating system user the splunk service is running as. If splunkd is running as root user, the attacker can read the content of any file in the server, including /etc/shadow and other sensitive configuration files. Thus, being an admin in the splunk UI allows an attacker to obtain information that may lead to escalation of privileges on the operating system where splunk is installed. The vendor was notified of this behavior, and declared not to consider it either a defect or a vulnerability. VI. SYSTEMS AFFECTED ------------------------- Version 4.3.3 and prior versions are vulnerable. VII. SOLUTION ------------------------- N/A. VIII. DISCLOSURE TIMELINE ------------------------- 7/27/12 - Vulnerability discovered. 8/3/12 - Vendor Contacted. 8/3/12 - Vendor Response "we don't consider this behaviour a design defect or vulnerability". 8/3/12 - Vendor informed about full disclosure in some days. 9/3/12 - Full disclosure IX. REFERENCES ------------------------- [1] http://management.silicon.com/itpro/0,39024675,39157789,00.htm [2] Security Power Tools. O'Reilly Media, Inc.. ISBN 0-596-00963-1. [3] Nagios 3 Enterprise Network Monitoring: Including Plug-Ins and Hardware Devices. Syngress. ISBN 1-59749-267-1. [4] http://gigaom.com/cloud/how-splunk-is-riding-it-search-toward-an-ipo/ [5] http://online.wsj.com/article/SB125237153923891221.html Start-Ups Aim to Help Tame Corporate Data, Pui-Wing Tam, Wall Street Journal, September 08, 2009 [6] http://www.citoresearch.com/content/business-intelligence-and-data-center [7] Central, CIO. Forbes. http://blogs.forbes.com/ciocentral/2010/12/15/how-cios-should-be-helping-marketers/ . [8] http://gigaom.com/cloud/how-splunk-is-riding-it-search-toward-an-ipo/ [9] http://venturebeat.com/2011/02/08/splunk-seattle-office-opens/ X. CREDITS ------------------------- The vulnerability has been discovered by Marcio Almeida (marcio.macedo@ciphersec.com.br) of CIPHER Intelligence Labs (www.ciphersec.net). XI. GREETINGS ------------------------- To Rodrigo Salvalagio rsalvalagio@gmail.com for support during this process. XI. LEGAL NOTICES ------------------------- The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. I accept no responsibility for any damage caused by the use or misuse of this information. -- - M�rcio Almeida Msc. Student of Security Information and Cryptoanalisis at Federal University of Pernambuco |