__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Center ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Apache HTTP Server on Win32 Vulnerability [CERT Vulnerability Note VU#124003] April 23, 2002 21:00 GMT Number M-070 ______________________________________________________________________________ PROBLEM: A vulnerability has been identified in the Apache HTTP Server running on Win32 systems. PLATFORM: The following Win32 systems running Apache HTTP Servers: Windows 9x, Windows Me, Windows NT/2000/XP. DAMAGE: An unauthenticated, remote attacker could execute commands on the vulnerable server with the privileges of the Apache process. SOLUTION: Upgrade to Apache 1.3.24 or 2.0.34-beta. ______________________________________________________________________________ VULNERABILITY The risk is HIGH. The vulnerability allows remote command ASSESSMENT: execution and arbitrary file viewing. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/m-070.shtml ORIGINAL BULLETIN: http://www.kb.cert.org/vuls/id/124003 ______________________________________________________________________________ [***** Start CERT Vulnerability Note VU#124003 *****] CERT Vulnerability Note VU#124003 Apache HTTP Server on Win32 systems does not securely handle input passed to CGI programs Overview A vulnerability in the Apache HTTP Server running on Win32 systems (Windows 9x/Me, Windows NT/2000/XP) could allow an attacker to execute commands with the privileges of the web server process. I. Description The Apache HTTP Server is a freely available web server that runs on a variety of operating systems including Unix, Linux, and Microsoft Windows (Win32). Apache supports the Common Gateway Interface (CGI) that defines a standard interface between the HTTP server and external applications. On Win32 systems, batch or command shell programs (files typically with .bat or .cmd extensions) can be executed via the CGI interface, and these programs are executed within a full command shell (command.com on Windows 9x/Me, cmd.exe in Windows NT/2000/XP). Ory Segal of Sanctum has reported a vulnerability in which Apache on Win32 does not securely handle the arguments passed to batch or command shell CGI programs. By crafting a CGI request containing the "|" (pipe) character, an attacker can cause the program to execute arbitrary commands with the privileges of the Apache process. By default, Apache is installed with local SYSTEM privileges in Windows NT, 2000, and XP. In Windows 9x/Me, all programs including Apache run with full privileges. II. Impact An unauthenticated, remote attacker could execute commands on the vulnerable server with the privileges of the Apache process. By default, Apache runs with local SYSTEM privileges in Windows NT, 2000, and XP. In Windows 9x/Me, Apache runs with full privileges. III. Solution Upgrade Apache This vulnerability is resolved in Apache 1.3.24 and 2.0.34-beta. Please see the release Announcement for version 1.3.24. The Apache HTTP Server is available from the Apache web site. Run Apache with User privileges On Windows NT, 2000, and XP systems, the Apache service can be configured to run as a specified user instead of local SYSTEM. By carefully specifying the privileges of the Apache user, an administrator can restrict the ability of a CGI program to access files and execute commands. Systems Affected Vendor Status Date Updated Apache Vulnerable 11-Apr-2002 References http://www.apache.org/dist/httpd/ http://www.apache.org/dist/httpd/CHANGES_1.3 http://www.apache.org/dist/httpd/Announcement.html http://www.securityfocus.com/bid/4335 http://online.securityfocus.com/archive/1/263370 http://www.w3.org/CGI/ http://hoohoo.ncsa.uiuc.edu/cgi/ Credit The CERT/CC acknowledges Ory Segal for reporting this vulnerability. This document was written by Art Manion. Other Information Date Public 03/21/2002 Date First Published 04/11/2002 10:43:48 AM Date Last Updated 04/22/2002 CERT Advisory CVE Name CAN-2002-0061 Metric 11.06 Document Revision 17 [***** End CERT Vulnerability Note VU#124003 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of CERT and Ory Segal for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Center, is the computer security incident response team for the U.S. Department of Energy (DOE) and the emergency backup response team for the National Institutes of Health (NIH). CIAC is located at the Lawrence Livermore National Laboratory in Livermore, California. CIAC is also a founding member of FIRST, the Forum of Incident Response and Security Teams, a global organization established to foster cooperation and coordination among computer security teams worldwide. CIAC services are available to DOE, DOE contractors, and the NIH. CIAC can be contacted at: Voice: +1 925-422-8193 (7x24) FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@ciac.org Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ Anonymous FTP: ftp.ciac.org PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. A list of FIRST member organizations and their constituencies can be obtained via WWW at http://www.first.org/. This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. LAST 10 CIAC BULLETINS ISSUED (Previous bulletins available from CIAC) M-062: Double Free Bug in zlib Compression Library M-063: Microsoft Internet Explorer Vulnerabilities CIACTech02-002: Microsoft Browser Helper Objects (BHO) Could Hide Malicious Code M-064: Cisco web interface vulnerabilities in ACS for Windows M-065: Red Hat Race Conditions in "logwatch" M-066: Microsoft Cumulative Patch for Internet Information Services (IIS) Vulnerabilities M-067: SGI Mail, mailx, sort, timed, and gzip Vulnerabilities M-068: Microsoft IE and Office for Macintosh Vulnerabilities M-069: Microsoft SQL Server Unchecked Buffer Vulnerabilities