CVE-2014-5012 in DOMPDF
Summary
by MITRE
DOMPDF before 0.6.2 allows denial of service.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 04/22/2023
The vulnerability identified as CVE-2014-5012 represents a denial of service flaw affecting DOMPDF versions prior to 0.6.2. DOMPDF is a widely-used PHP library that converts HTML documents into PDF format, making it an essential component in many web applications requiring document generation capabilities. This vulnerability specifically targets the library's processing of certain HTML input structures that can cause the application to consume excessive system resources or enter an infinite loop during PDF generation. The flaw manifests when the library encounters malformed or specially crafted HTML content that triggers recursive processing behaviors within the DOM parsing and rendering mechanisms.
The technical nature of this vulnerability stems from inadequate input validation and resource management within the DOMPDF processing pipeline. When processing certain HTML constructs, particularly those involving nested or malformed elements, the library can enter recursive parsing states that consume increasing amounts of memory and processing cycles. This behavior is classified under CWE-400 as an Uncontrolled Resource Consumption vulnerability, where the system's resources are exhausted due to improper handling of input data. The flaw does not involve direct code execution or privilege escalation but rather focuses on resource exhaustion that renders the application unavailable to legitimate users.
From an operational perspective, this vulnerability poses significant risks to web applications that rely on DOMPDF for document generation. Attackers can exploit this flaw by submitting carefully crafted HTML content to PDF generation endpoints, causing the application server to consume excessive CPU cycles and memory resources. The impact extends beyond simple service disruption as the denial of service can affect entire application availability, potentially leading to business interruption and degraded user experience. This vulnerability is particularly dangerous in multi-tenant environments or applications with high traffic volumes where a single malicious request can cause cascading failures across the system.
The exploitation of this vulnerability aligns with ATT&CK technique T1499.004 which covers Network Denial of Service. Organizations using DOMPDF should implement immediate mitigations including upgrading to version 0.6.2 or later, implementing input validation and sanitization measures, and establishing resource limits on PDF generation processes. Additional protective measures include rate limiting for PDF generation endpoints, monitoring for unusual resource consumption patterns, and implementing proper error handling to prevent resource exhaustion. The vulnerability serves as a reminder of the importance of validating all input data and implementing robust resource management practices in web applications. Security teams should also consider implementing web application firewalls to detect and block suspicious HTML content patterns that could trigger this vulnerability, as well as conducting regular security assessments to identify other potential resource exhaustion vulnerabilities in their software dependencies.