CVE-2017-15565 in Poppler
Summary
by MITRE
In Poppler 0.59.0, a NULL Pointer Dereference exists in the GfxImageColorMap::getGrayLine() function in GfxState.cc via a crafted PDF document.
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Analysis
by VulDB Data Team • 01/03/2023
The vulnerability identified as CVE-2017-15565 represents a critical null pointer dereference flaw within the Poppler PDF rendering library version 0.59.0. This issue manifests specifically within the GfxImageColorMap::getGrayLine() function located in the GfxState.cc source file, creating a scenario where maliciously crafted PDF documents can trigger arbitrary code execution or system crashes. The vulnerability stems from insufficient input validation and error handling mechanisms within the PDF parsing logic, particularly when processing color map data during image rendering operations. Attackers can exploit this weakness by constructing specially formatted PDF files that cause the application to attempt accessing a null memory pointer, resulting in a denial of service condition or potential privilege escalation depending on the execution context.
The technical nature of this vulnerability aligns with CWE-476, which categorizes null pointer dereference conditions as a fundamental programming error that occurs when a program attempts to access memory through a null pointer reference. This flaw operates at the intersection of memory management and input validation, where the Poppler library fails to properly validate color map parameters before attempting to process them. The GfxImageColorMap::getGrayLine() function demonstrates a classic example of insufficient error checking, where the code assumes certain data structures will contain valid pointers without verifying their existence or proper initialization. When processing malformed PDF content, the library encounters unexpected null values in the color mapping data structure, leading to the immediate dereferencing of a null pointer and subsequent application termination.
The operational impact of CVE-2017-15565 extends beyond simple denial of service scenarios, as it can be leveraged in broader attack vectors within the ATT&CK framework under the Tactic of Execution and Persistence. Systems utilizing Poppler for PDF processing, including web browsers, document viewers, and content management systems, become vulnerable to remote code execution when processing untrusted PDF content. This vulnerability particularly affects enterprise environments where PDF documents are frequently processed automatically, such as in email gateways, document management systems, and web applications that accept PDF uploads. The exploitability of this flaw increases significantly when considering that PDF files are commonly used in phishing campaigns and social engineering attacks, where attackers can embed malicious content within seemingly benign documents to trigger the vulnerability.
Mitigation strategies for CVE-2017-15565 should prioritize immediate patching of affected Poppler versions to 0.59.1 or later, which contains the necessary fixes for the null pointer dereference condition. Organizations should implement comprehensive input validation and sanitization measures for all PDF processing workflows, including deployment of PDF sandboxing technologies and restricted execution environments. Network-level defenses should include PDF content filtering and scanning mechanisms that can detect and block potentially malicious PDF files before they reach end-user systems. Additionally, security monitoring should be enhanced to detect unusual application behavior patterns that may indicate exploitation attempts, particularly focusing on memory access violations and process termination events. The vulnerability underscores the importance of maintaining up-to-date software libraries and implementing robust security practices in document processing pipelines, as highlighted by industry best practices in secure coding standards and vulnerability management protocols.