8.8 CVE-2016-6277

An attacker targets a system that uses JavaScript Object Notation (JSON) as a transport mechanism between the client and the server (common in Web 2.0 systems using AJAX) to steal possibly confidential information transmitted from the server back to the client inside the JSON object by taking advantage of the loophole in the browser's Same Origin Policy that does not prohibit JavaScript from one website to be included and executed in the context of another website. [Understand How to Request JSON Responses from the Target System] An attacker first explores the target system to understand what URLs need to be provided to it in order to retrieve JSON objects that contain information of interest to the attacker. [Craft a malicious website] [Launch JSON hijack] An attacker lures the victim to the malicious website or leverages other means to get their malicious code executing in the victim's browser. Once that happens, the malicious code makes a request to the victim target system to retrieve a JSON object with sensitive information. The request includes the victim's session cookie if the victim is logged in.

An attacker initiates cross domain HTTP / GET requests and times the server responses. The timing of these responses may leak important information on what is happening on the server. Browser's same origin policy prevents the attacker from directly reading the server responses (in the absence of any other weaknesses), but does not prevent the attacker from timing the responses to requests that the attacker issued cross domain. [Determine service to send cross domain requests to] The adversary first determines which service they will be sending the requests to [Send and time various cross domain requests] Adversaries will send a variety of cross domain requests to the target, timing the time it takes for the target to respond. Although they won't be able to read the response, the adversary can use the time to infer information about what the service did upon receiving the request. [Infer information from the response time] After obtaining reponse times to various requests, the adversary will compare these times and infer potentially sensitive information. An example of this could be asking a service to retrieve information and random usernames. If one request took longer to process, it is likely that a user with that username exists, which could be useful knowledge to an adversary.

An attacker harvests identifying information about a victim via an active session that the victim's browser has with a social networking site. A victim may have the social networking site open in one tab or perhaps is simply using the "remember me" feature to keep their session with the social networking site active. An attacker induces a payload to execute in the victim's browser that transparently to the victim initiates a request to the social networking site (e.g., via available social network site APIs) to retrieve identifying information about a victim. While some of this information may be public, the attacker is able to harvest this information in context and may use it for further attacks on the user (e.g., spear phishing).

An attacker crafts malicious web links and distributes them (via web pages, email, etc.), typically in a targeted manner, hoping to induce users to click on the link and execute the malicious action against some third-party application. If successful, the action embedded in the malicious link will be processed and accepted by the targeted application with the users' privilege level. This type of attack leverages the persistence and implicit trust placed in user session cookies by many web applications today. In such an architecture, once the user authenticates to an application and a session cookie is created on the user's system, all following transactions for that session are authenticated using that cookie including potential actions initiated by an attacker and simply "riding" the existing session cookie. [Explore target website] The attacker first explores the target website to determine pieces of functionality that are of interest to them (e.g. money transfers). The attacker will need a legitimate user account on the target website. It would help to have two accounts. [Create a link that when clicked on, will execute the interesting functionality.] The attacker needs to create a link that will execute some interesting functionality such as transfer money, change a password, etc. [Convince user to click on link] Finally, the attacker needs to convince a user that is logged into the target website to click on a link to execute the CSRF attack.