Yandex MC Content-Security-Policy Bypass Scanner

Yandex MC is an analytical service used by businesses to track user behavior and interactions on their websites. It is predominantly used by marketing teams, web analysts, and IT security professionals to gather data insights and improve user experience. However, vulnerabilities within such tools can also become gateways for exploitation, leading to unauthorized information access. By identifying and mitigating potential security flaws, companies can protect user data and maintain the integrity of their online presence. Additionally, scanners ensure compliance with data protection regulations, helping avoid legal and financial repercussions. Hence, maintaining the security of analytics frameworks like Yandex MC is crucial for both business operations and user trust.

This scanner detects a Content-Security-Policy (CSP) bypass vulnerability in Yandex MC, which can lead to cross-site scripting issues. CSP is a security feature that helps prevent XSS attacks by restricting what resources can be loaded by a webpage. By exploiting a weakness in the CSP of Yandex MC, attackers may insert malicious scripts into web pages. This identified vulnerability indicates a possibility of inserting or modifying legitimate scripts to execute unauthorized actions. Detecting such vulnerabilities is vital as they can be exploited to gain control of a user's session or redirect users to malicious sites. Such a breach can result in significant security incidents if not promptly addressed.

The Yandex MC CSP Bypass involves a technical loophole where the CSP settings can be circumvented, allowing an attacker to inject scripts. This flaw is specifically located in the header part, checking for the presence of words like "Content-Security-Policy" and "yandex.ru". Additionally, the vulnerability is explored through headless navigation and payload injection methods. Technical execution includes utilizing a `GET` method and using a script injection technique. The vulnerable parameter involves manipulating the query part through encoded payloads. Moreover, headless operations simulate the user actions to test the effectiveness of the CSP settings in thwarting script-based exploits.

Exploitation of this vulnerability can lead to unauthorized data access, where attackers intercept information meant for user-analysis purposes. It may also enable attackers to deploy further attacks by redirecting users to malicious domains. Cross-site scripting (XSS) can result in user session hijacking, unauthorized actions carried out on behalf of users, and data leakage risks. Additionally, successful exploitation could undermine the trust users place in the service, affecting its reputation. Therefore, addressing CSP bypass vulnerabilities is critical in maintaining site integrity and safeguarding sensitive data.

REFERENCES

• https://github.com/renniepak/CSPBypass/blob/main/data.tsv