CVE-2017-14926 in Poppler
Summary
by MITRE
In Poppler 0.59.0, a NULL Pointer Dereference exists in AnnotRichMedia::Content::Content in Annot.cc via a crafted PDF document.
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Analysis
by VulDB Data Team • 12/30/2022
The vulnerability identified as CVE-2017-14926 represents a critical NULL pointer dereference flaw within the Poppler PDF rendering library version 0.59.0. This issue manifests specifically within the AnnotRichMedia::Content::Content class in the Annot.cc source file, creating a potential crash condition that could be exploited by malicious actors. The vulnerability arises when processing specially crafted PDF documents that contain malformed rich media annotations, which triggers the library to attempt dereferencing a null pointer during the annotation parsing process. This type of vulnerability falls under the category of memory safety issues and is particularly concerning given Poppler's widespread use in various PDF processing applications and systems.
The technical exploitation of this vulnerability occurs when a PDF document contains a malformed rich media annotation structure that causes the AnnotRichMedia::Content::Content constructor or related methods to access a null pointer reference. This typically happens when the annotation parsing logic fails to properly validate the structure of rich media content elements, leading to uninitialized pointer usage during subsequent processing operations. The flaw represents a classic example of improper input validation and error handling within the PDF parsing pipeline, where the library does not adequately check for null or malformed annotation data before attempting to process it. According to CWE guidelines, this vulnerability maps to CWE-476 which specifically addresses NULL Pointer Dereference conditions, and it demonstrates poor defensive programming practices in handling untrusted input data.
The operational impact of CVE-2017-14926 extends beyond simple application crashes, as it can be leveraged to create denial of service conditions that disrupt legitimate PDF processing workflows. When exploited, this vulnerability can cause applications using Poppler to terminate unexpectedly, potentially affecting web browsers, PDF viewers, and document processing systems that rely on this library. The vulnerability is particularly dangerous in automated processing environments where PDF files are ingested without proper validation, as it could enable attackers to craft malicious documents that systematically crash processing systems. This behavior aligns with ATT&CK technique T1499.004 which involves network disruption through resource exhaustion or system crashes, and it demonstrates how seemingly minor parsing flaws can create significant operational disruptions in document processing infrastructure.
Mitigation strategies for CVE-2017-14926 should focus on immediate library upgrades to versions that contain the patched implementation, as the vulnerability was addressed in subsequent Poppler releases. Organizations should implement comprehensive PDF validation procedures that include signature checking and content sanitization before processing potentially malicious documents. Additionally, deploying sandboxing mechanisms around PDF processing applications can help contain the impact of exploitation attempts, preventing crashes from affecting the broader system. Network-level defenses such as PDF inspection appliances and web application firewalls should also be configured to detect and block suspicious PDF content patterns that may indicate exploitation attempts. The vulnerability serves as a reminder of the importance of robust input validation and proper error handling in security-critical libraries, particularly those handling untrusted document formats that are widely distributed across various platforms and applications.