Permissive Cross-domain Security Policy with Untrusted Domains
This vulnerability occurs when a web application's cross-domain security policy, like a Content Security Policy (CSP), explicitly allows communication with untrusted or overly permissive external domains.
A permissive cross-domain policy undermines a key web security control. By listing untrusted domains or using overly broad wildcards (e.g., *.example.com), you grant those external sites the ability to interact with your application's data and user session, effectively inviting potential attackers into a trusted context. Attackers hosted on these permitted domains can often launch exploits, such as data theft or session hijacking, without any visible warning to the end user. This makes the vulnerability particularly dangerous, as a compromise can occur silently during normal browsing, bypassing the intended protections of the security policy.
Impact: Execute Unauthorized Code or CommandsBypass Protection MechanismRead Application DataVaries by Context
With an overly permissive policy file, an attacker may be able to bypass the web browser's same-origin policy and conduct many of the same attacks seen in Cross-Site Scripting (Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')). An attacker can exploit the weakness to transfer private information from the victim's machine to the attacker, manipulate or steal cookies that may include session information, create malicious requests to a web site on behalf of the victim, or execute malicious code on the end user systems. Other damaging attacks include the disclosure of end user files, installation of Trojan horse programs, redirecting the user to some other page or site, running ActiveX controls (under Microsoft Internet Explorer) from sites that a user perceives as trustworthy, and modifying presentation of content.
Strategy: Attack Surface Reduction
Strategy: Attack Surface Reduction
Strategy: Environment Hardening
ID : DX-208
These cross-domain policy files mean to allow Flash and Silverlight applications hosted on other domains to access its data:Code Example:
xmlCode Example:
xml