20-01-2003
Published: 2003-01-20 19:35:41
Updated: 2003-01-20 19:35:41
Internet Security Systems Security Advisory January 20, 2003 PeopleSoft XML External Entities Vulnerability Synopsis: ISS X-Force has discovered a flaw in the PeopleSoft Application Messaging Gateway. PeopleSoft enterprise software enables the management of all manner of business functions, including human resources, customer relations, supply chain, and finance. The PeopleSoft Application Messaging Gateway provides a Web-based interface for PeopleSoft functionality and allows for communication and synchronization between PeopleSoft products non-PeopleSoft products. Impact: The Application Messaging Gateway is configured to run by default on the PeopleSoft Web server, and is accessible as a Java servlet. Attackers can use an XML External Entities (XXE) attack to read any file on the vulnerable PeopleSoft application server under the security context of the Web server process. This attack may lead to the exposure of confidential information stored in vulnerable PeopleSoft installations. Affected Versions: PeopleTools 8.1x prior to 8.19, included with most PeopleSoft installations, including but not limited to: PeopleSoft HCM (Human Capital Management) PeopleSoft CRM (Customer Relationship Management) PeopleSoft EPM (Enterprise Performance Management) PeopleSoft FMS (Financial Management Solutions) PeopleSoft SCM (Supply Chain Management) PeopleSoft ESA (Enterprise Server Automation) PeopleSoft SRM (Supplier Relationship Management) Note: PeopleTools 8.4x is not vulnerable. Description: The Application Messaging Gateway can be administered via the Gateway Administration servlet, accessible to all by default. This servlet can easily be disabled, but most administrators do not regard it as a security risk. The servlet can be used to add handlers, to which data sent to the gateway is delivered. PeopleSoft includes a handler to push data out of the PeopleSoft system, called the SimpleFileHandler. Once this handler has been added via the gateway administration servlet, XML data can be submitted via an HTTP POST request. When responding to a request, certain elements of the data submitted are selected using an XML parser, and several XML tags are returned to the remote user within the response. It is possible to include an XML external entity within those fields, which causes the XML parser to read arbitrary files. Data is returned to the remote user within the response. It is also possible to cause the vulnerable servlet to open arbitrary TCP connections. Recommendations: Internet Scanner X-Press Update 6.24 includes a check to assess the vulnerability described in this advisory. XPU 6.24 is available now from the ISS Download Center at: http://www.iss.net/download. ISS X-Force recommends that all PeopleSoft administrators block or restrict access to the servlets in question. X-Force also recommends that administrators take advantage of the security mechanisms that BEA WebLogic Servers provide to restrict access based on the requirements of users. Administrators should examine the following configuration properties and tune them to their individual environments. To address the issues described in this advisory, the following servlets should be restricted within the "weblogic.properties" file: weblogic.httpd.register.servlets/gateway.administration=psft.pt8.config.ConfigServlet weblogic.allow.execute.weblogic.servlet.servlets/gateway.administration=system weblogic.httpd.register.servlets/gateway.handlers=psft.pt8.reader.ReaderServlet weblogic.allow.execute.weblogic.servlet.servlets/gateway.handlers=system weblogic.httpd.register.servlets/gateway=psft.pt8.gateway.GatewayServlet weblogic.allow.execute.weblogic.servlet.servlets/gateway=system PeopleSoft has addressed all of the issues described in this advisory in PeopleTools 8.19, available on PeopleSoft?s Customer Connection site in early February. As a workaround, in addition to recommendations mentioned above, remove the SimpleFileHandler files if SimpleFileHandler is not required by deleting the /psft/pt8/filehandler directory under the servlets directory on the Web server. Additional Information: The Common Vulnerabilities and Exposures (CVE) project has assigned the name CAN-2002-1252 to this issue. This is a candidate for inclusion in the CVE list http://cve.mitre.org), which standardizes names for security problems. XXE attacks were recently described by Gregory Steuck in an advisory posted to the BugTraq mailing list: http://archives.neohapsis.com/archives/bugtraq/2002-10/0411.html Credit: This vulnerability was discovered and researched by Neel Mehta of the ISS X-Force. ______ About Internet Security Systems (ISS) Founded in 1994, Internet Security Systems (ISS) (Nasdaq: ISSX) is a pioneer and world leader in software and services that protect critical online resources from an ever-changing spectrum of threats and misuse. Internet Security Systems is headquartered in Atlanta, GA, with additional operations throughout the Americas, Asia, Australia, Europe and the Middle East. Copyright (c) 2003 Internet Security Systems, Inc. All rights reserved worldwide. Permission is hereby granted for the electronic redistribution of this document. It is not to be edited or altered in any way without the express written consent of the Internet Security Systems X-Force. If you wish to reprint the whole or any part of this document in any other medium excluding electronic media, please email xforce@iss.net for permission. Disclaimer: The information within this paper may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information. X-Force PGP Key available on MIT's PGP key server and PGP.com's key server, as well as at http://www.iss.net/security_center/sensitive.php Please send suggestions, updates, and comments to: X-Force xforce@iss.net of Internet Security Systems, Inc.
