CVE-2023-0835 in markdown-pdf
Summary
by MITRE • 04/05/2023
markdown-pdf version 11.0.0 allows an external attacker to remotely obtain arbitrary local files. This is possible because the application does not validate the Markdown content entered by the user.
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Analysis
by VulDB Data Team • 07/12/2025
The vulnerability identified as CVE-2023-0835 affects the markdown-pdf application version 11.0.0, presenting a critical security risk that enables remote attackers to access arbitrary local files on the system. This flaw resides in the application's insufficient input validation mechanisms, specifically within the Markdown content processing pipeline. The vulnerability stems from the application's failure to properly sanitize or validate user-provided Markdown input before rendering it into PDF documents, creating a path for malicious actors to exploit the system's file access capabilities.
This security weakness operates through a server-side request forgery pattern where crafted Markdown content can trigger the application to read and include local files in the generated PDF output. The vulnerability is categorized under CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which is a well-documented weakness in software applications that fail to properly validate file paths. Attackers can leverage this flaw by embedding malicious file references within their Markdown content, potentially accessing sensitive system files, configuration data, or other locally stored information that should remain protected from unauthorized access.
The operational impact of this vulnerability is severe as it allows for remote information disclosure attacks that can compromise the confidentiality of system resources. An attacker with remote access to the vulnerable application can potentially extract sensitive data including but not limited to system configuration files, database credentials, application source code, or user data stored locally on the server. This represents a significant threat to organizations relying on markdown-pdf for document generation, as it could lead to data breaches, system compromise, or further lateral movement within the network infrastructure. The attack vector is particularly dangerous because it requires minimal privileges and can be executed through standard web-based interfaces without requiring specialized tools or deep system knowledge.
Mitigation strategies for CVE-2023-0835 should focus on implementing robust input validation and sanitization mechanisms within the markdown-pdf application. Organizations should immediately update to the latest available version of the application where this vulnerability has been addressed through proper input validation. Additionally, implementing proper file access controls and restricting the application's ability to read arbitrary local files through sandboxing or containerization techniques can significantly reduce the attack surface. Network segmentation and access controls should be enforced to limit exposure of the vulnerable application to untrusted users. The implementation of proper content security policies and the use of secure coding practices that prevent path traversal attacks should be enforced across all applications processing user-generated content. This vulnerability aligns with ATT&CK technique T1074.001 - Data Staged, where adversaries stage data to be exfiltrated, and represents a critical gap in the security posture that requires immediate attention through both patch management and architectural security improvements.