CVE-2022-41710 in Markdownify
Summary
by MITRE • 11/04/2022
Markdownify version 1.4.1 allows an external attacker to remotely obtain arbitrary local files on any client that attempts to view a malicious markdown file through Markdownify. This is possible because the application does not have a CSP policy (or at least not strict enough) and/or does not properly validate the contents of markdown files before rendering them.
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Analysis
by VulDB Data Team • 12/04/2022
The vulnerability identified as CVE-2022-41710 affects Markdownify version 1.4.1, a client-side markdown rendering application that processes markdown files for display in web browsers. This security flaw represents a critical server-side request forgery (SSRF) and local file inclusion (LFI) vulnerability that enables remote attackers to access arbitrary local files on client systems. The vulnerability stems from insufficient input validation and the absence of proper content security policies that would normally prevent such unauthorized file access patterns.
The technical implementation of this vulnerability occurs when a malicious markdown file is crafted with specific payload patterns that exploit the application's rendering engine. Without adequate content security policy enforcement, the application fails to validate or sanitize markdown content before processing, allowing attackers to embed file system references that can be resolved locally on the client machine. This weakness specifically targets the application's handling of relative paths, file protocols, or embedded references within markdown syntax that should normally be restricted or escaped during rendering.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to potentially access sensitive local files including configuration data, user credentials, system logs, or other confidential information stored on the client system. The vulnerability affects any client that processes markdown files through the vulnerable Markdownify application, making it particularly dangerous in environments where users may unknowingly encounter malicious markdown files in email attachments, shared documents, or web-based collaboration platforms. Attackers can leverage this vulnerability to perform reconnaissance, extract sensitive data, or potentially escalate privileges by accessing system configuration files or credential stores.
Security mitigations for this vulnerability should focus on implementing robust input validation and content sanitization mechanisms that prevent the processing of potentially malicious file references within markdown content. Organizations should enforce strict content security policies that block local file access attempts and implement proper markdown parsing libraries that sanitize file system references. The vulnerability aligns with CWE-22 (Improper Limiting of a Pathname to a Restricted Directory) and CWE-94 (Improper Control of Generation of Code) while potentially mapping to ATT&CK technique T1059.001 (Command and Scripting Interpreter: PowerShell) and T1566 (Phishing) when considering the attack delivery vectors. The most effective remediation involves updating to a patched version of Markdownify that properly validates file references and enforces strict content security policies to prevent unauthorized local file access during markdown rendering operations.