Clientless SSL VPN products break web browser domain-based security models

Vulnerability Description

Multiple clientless SSL VPN products that run in web browsers, including Stonesoft StoneGate; Cisco ASA; SonicWALL E-Class SSL VPN and SonicWALL SSL VPN; SafeNet SecureWire Access Gateway; Juniper Networks Secure Access; Nortel CallPilot; Citrix Access Gateway; and other products, when running in configurations that do not restrict access to the same domain as the VPN, retrieve the content of remote URLs from one domain and rewrite them so they originate from the VPN's domain, which violates the same origin policy and allows remote attackers to conduct cross-site scripting attacks, read cookies that originated from other domains, access the Web VPN session to gain access to internal resources, perform key logging, and conduct other attacks. NOTE: it could be argued that this is a fundamental design problem in any clientless VPN solution, as opposed to a commonly-introduced error that can be fixed in separate implementations. Therefore a single CVE has been assigned for all products that have this design

References

• https://www.kb.cert.org/vuls/id/261869
• https://security.paloaltonetworks.com/PAN-SA-2025-0005