CVE-2019-14517 in Editor.md
Summary
by MITRE
pandao Editor.md 1.5.0 allows XSS via the Javascript: string.
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Analysis
by VulDB Data Team • 11/20/2023
The vulnerability identified as CVE-2019-14517 affects pandao Editor.md version 1.5.0 and represents a cross-site scripting vulnerability that arises from improper input validation within the markdown editor component. This flaw specifically manifests when the application processes user-supplied content that contains the JavaScript: string prefix, which can be exploited to execute malicious scripts in the context of the victim's browser. The vulnerability stems from the editor's insufficient sanitization of input data, particularly when handling markdown syntax that includes JavaScript protocol handlers. This issue falls under the CWE-79 category of Cross-Site Scripting, which is a fundamental web application security weakness that allows attackers to inject client-side scripts into web pages viewed by other users. The attack vector is particularly concerning because it leverages the legitimate functionality of markdown editors to process code blocks and other content types that may contain embedded script references.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious input that includes the JavaScript: protocol followed by malicious script code within the editor's markdown parsing functionality. When the vulnerable editor processes this input, it fails to properly escape or sanitize the JavaScript: string, allowing it to be interpreted as executable code rather than plain text. This misconfiguration creates an environment where user-generated content can be transformed into active attack vectors, particularly when the editor's preview or rendering functionality executes the malicious payload. The vulnerability impacts the integrity of the application's content processing pipeline and can potentially lead to session hijacking, credential theft, or other malicious activities when users view the compromised content. The flaw demonstrates a classic failure in input validation and output encoding, which are fundamental security principles that should prevent such protocol-based injection attacks.
The operational impact of CVE-2019-14517 extends beyond simple script execution, as it can compromise the entire user session and potentially provide attackers with access to sensitive data within the application context. When users view content containing the malicious JavaScript: string, their browsers execute the embedded code, which can lead to various security consequences including but not limited to cookie theft, redirection to malicious sites, or data exfiltration. The vulnerability is particularly dangerous in collaborative environments where multiple users contribute content to shared documents, as a single compromised entry can affect all users who view the content. This type of vulnerability also undermines user trust in the application's security posture and can result in regulatory compliance issues for organizations that handle sensitive information. The attack can be amplified through social engineering techniques where attackers convince users to view maliciously crafted content, making the vulnerability particularly difficult to prevent without proper input sanitization.
Mitigation strategies for CVE-2019-14517 should focus on implementing comprehensive input validation and output encoding mechanisms within the Editor.md component. Organizations should immediately upgrade to patched versions of pandao Editor.md where available, as the vulnerability is well-documented and has likely been addressed in subsequent releases. The recommended approach includes implementing strict content sanitization that filters out or escapes JavaScript: and similar protocol strings before processing user input. Security measures should also incorporate proper HTML escaping of all user-generated content, particularly when rendering markdown content in web browsers. Organizations should consider implementing content security policies that restrict script execution and prevent the loading of external resources that could be used to exploit this vulnerability. Additionally, regular security testing including dynamic application security testing and manual penetration testing should be performed to identify similar vulnerabilities in other components of the application stack. The remediation efforts should align with the ATT&CK framework's T1203 technique for exploitation of web applications, ensuring that defenses are layered and comprehensive against protocol-based injection attacks.