CVE-2017-5833 in Adserver
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the invocation code generation for interstitial zones in Revive Adserver before 4.0.1 allows remote attackers to inject arbitrary web script or HTML via unspecified parameters.
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Analysis
by VulDB Data Team • 09/04/2020
The CVE-2017-5833 vulnerability represents a critical cross-site scripting flaw within the Revive Adserver platform, specifically affecting versions prior to 4.0.1. This vulnerability resides in the invocation code generation mechanism for interstitial zones, which are typically used to display advertisements that appear between content pages or during user interactions. The flaw allows remote attackers to inject malicious web scripts or HTML content through unspecified parameters that are processed during the generation of advertisement invocation code. This type of vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is one of the most prevalent and dangerous web application security flaws identified by the Common Weakness Enumeration project.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding within the interstitial zone code generation process. When the system processes user-supplied parameters to generate advertisement invocation scripts, it fails to properly sanitize or escape special characters that could be interpreted as HTML or JavaScript code. Attackers can exploit this by crafting malicious payloads that, when processed through the vulnerable code generation logic, get embedded directly into the generated HTML output. The unspecified parameters mentioned in the description suggest that multiple input vectors within the interstitial zone configuration could serve as attack surfaces, making the vulnerability particularly insidious as it may be exploitable through various configuration options or user inputs.
The operational impact of CVE-2017-5833 extends beyond simple data theft or defacement, as it provides attackers with a persistent vector for executing malicious code within the context of user browsers. When users interact with advertisements served through vulnerable interstitial zones, the injected scripts can execute in the user's browser session, potentially leading to session hijacking, credential theft, or redirection to malicious sites. The vulnerability can be leveraged to perform actions such as stealing cookies, modifying page content, or even executing arbitrary commands on the victim's system, depending on the specific implementation details. This aligns with the ATT&CK framework's technique T1566 for Phishing and T1059 for Command and Scripting Interpreter, as attackers can use this vulnerability to establish persistent access through malicious scripts.
Organizations using Revive Adserver versions prior to 4.0.1 face significant security risks, as this vulnerability can be exploited without requiring authentication or specific user interaction beyond viewing the affected advertisements. The impact is particularly severe for publishers who rely heavily on interstitial advertising, as these zones typically appear during high-traffic periods and provide maximum exposure for malicious payloads. Mitigation strategies should include immediate upgrade to Revive Adserver version 4.0.1 or later, which contains the necessary patches to address the input validation issues. Additionally, administrators should implement comprehensive input sanitization measures, including the use of Content Security Policy headers, proper HTML escaping of dynamic content, and regular security audits of advertisement code generation processes. The vulnerability demonstrates the critical importance of input validation in web applications and aligns with security best practices outlined in OWASP Top Ten and NIST Cybersecurity Framework, emphasizing the need for defense-in-depth approaches to protect against injection vulnerabilities.