CVE-2020-19007 in Blog
Summary
by MITRE
Halo blog 1.2.0 allows users to submit comments on blog posts via /api/content/posts/comments. The javascript code supplied by the attacker will then execute in the victim user's browser.
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Analysis
by VulDB Data Team • 08/26/2020
This vulnerability exists in Halo blog version 1.2.0 where the comment submission functionality at /api/content/posts/comments fails to properly sanitize user input before rendering it in the browser context. The flaw represents a classic cross-site scripting vulnerability that enables attackers to inject malicious javascript code through the comment submission process. When victims view blog posts containing these malicious comments, the injected javascript executes within their browser session, potentially compromising their security and privacy. The vulnerability stems from inadequate input validation and output encoding mechanisms that should prevent the execution of untrusted code in web contexts. According to CWE-79, this manifests as a failure to sanitize user-supplied data before incorporating it into dynamically generated web content. The attack vector operates through the standard comment submission interface, making it accessible to attackers who can leverage this functionality to deliver malicious payloads to other users.
The operational impact of this vulnerability extends beyond simple script execution as it can enable sophisticated attack chains targeting user sessions and data. Attackers can exploit this weakness to steal session cookies, redirect users to malicious sites, perform actions on behalf of authenticated users, or harvest sensitive information from the victim's browsing context. The vulnerability affects all users who have the ability to submit comments, including both registered users and anonymous commenters, making it particularly dangerous in environments where comment moderation is insufficient. This weakness aligns with ATT&CK technique T1566.001 which describes the use of malicious content to execute code in user browsers through web-based attack vectors. The vulnerability represents a critical security gap that undermines the trust model of the blogging platform and exposes users to various forms of automated exploitation.
Mitigation strategies should focus on implementing robust input validation and output encoding measures to prevent malicious code injection. The system must sanitize all user-supplied content before rendering it in the browser context, applying context-appropriate escaping mechanisms for javascript, html, and other potentially dangerous content types. Organizations should implement content security policies that restrict script execution and employ proper input validation at multiple layers of the application. The fix should include comprehensive sanitization of comment data before storage and retrieval, ensuring that any javascript code is properly escaped or removed. Additionally, administrators should consider implementing rate limiting and comment moderation features to reduce the attack surface and prevent automated exploitation. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other application components, as this type of weakness often indicates broader security gaps in web application development practices.