=====[BEGIN-ACROS-REPORT]===== PUBLIC ========================================================================= ACROS Security Problem Report #2004-10-14-3 ------------------------------------------------------------------------- ASPR #2004-10-14-3: Unsanitized Session ID Cookie Allows Modifying Server Response ========================================================================= Document ID: ASPR #2004-10-14-3-PUB Vendor: Macromedia (http://www.macromedia.com) Target: JRun 4 for Windows, Service Pack 1a Impact: It is possible to have JRun server issue an arbitrary HTTP header or body Severity: Medium Status: Official patch available Discovered by: Mitja Kolsek of ACROS Security CVE name: - Current version http://www.acrossecurity.com/aspr/ASPR-2004-10-14-3-PUB.txt Summary ======= An HTTP response splitting vulnerability (see [1]) exists in JRun server session management. It allows an attacker to issue an arbitrary HTTP header (e.g., a session cookie) or HTTP body (e.g., causing a cross site scripting) to a browser. Product Coverage ================ - JRun 4 for Windows, Service Pack 1a - affected All updaters applied, up to and excluding JRun4 Updater 4. Other versions may also be affected. Analysis ======== Using HTTP response splitting, it is possible to arbitrarily modify server's response. This feature can be used very effectively for poisoning HTTP proxy servers' cache (see [1]), for for session fixation (see [2]) and cross site scripting attacks. Solution ======== Macromedia has issued a security bulletin [3] and published JRun4 Updater 4, which fixes this issue. Affected users can download the updater from http://www.macromedia.com/support/jrun/updaters.html References ========== [1] Amit Klein, "Divide and Conquer" http://www.sanctuminc.com/pdf/Whitepaper_HTTPResponse.pdf [2] ACROS Security, "Session Fixation Vulnerability in Web-based Applications" http://www.acrossecurity.com/papers/session_fixation.pdf [3] Macromedia Security Bulletin MPSB04-08 http://www.macromedia.com/devnet/security/security_zone/mpsb04-08.html Acknowledgments =============== We would like to acknowledge Macromedia for response to our notification of the identified vulnerability. Contact ======= ACROS d.o.o. Makedonska ulica 113 SI - 2000 Maribor e-mail: security@acrossecurity.com web: http://www.acrossecurity.com phone: +386 2 3000 280 fax: +386 2 3000 282 ACROS Security PGP Key http://www.acrossecurity.com/pgpkey.asc [Fingerprint: FE9E 0CFB CE41 36B0 4720 C4F1 38A3 F7DD] ACROS Security Advisories http://www.acrossecurity.com/advisories.htm ACROS Security Papers http://www.acrossecurity.com/papers.htm ASPR Notification and Publishing Policy http://www.acrossecurity.com/asprNotificationAndPublishingPolicy.htm Disclaimer ========== The content of this report is purely informational and meant only for the purpose of education and protection. ACROS d.o.o. shall in no event be liable for any damage whatsoever, direct or implied, arising from use or spread of this information. All identifiers (hostnames, IP addresses, company names, individual names etc.) used in examples and demonstrations are used only for explanatory purposes and have no connection with any real host, company or individual. In no event should it be assumed that use of these names means specific hosts, companies or individuals are vulnerable to any attacks nor does it mean that they consent to being used in any vulnerability tests. The use of information in this report is entirely at user's risk. Revision History ================ October 14, 2004: Initial release Copyright ========= (c) 2004 ACROS d.o.o. Forwarding and publishing of this document is permitted providing the content between "[BEGIN-ACROS-REPORT]" and "[END-ACROS-REPORT]" marks remains unchanged. =====[END-ACROS-REPORT]=====