CVE-2007-0104 in KDE
Summary
by MITRE
The Adobe PDF specification 1.3, as implemented by (a) xpdf 3.0.1 patch 2, (b) kpdf in KDE before 3.5.5, (c) poppler before 0.5.4, and other products, allows remote attackers to have an unknown impact, possibly including denial of service (infinite loop), arbitrary code execution, or memory corruption, via a PDF file with a (1) crafted catalog dictionary or (2) a crafted Pages attribute that references an invalid page tree node.
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Analysis
by VulDB Data Team • 04/24/2019
This vulnerability resides within the PDF parsing implementations of several widely-used open source libraries and applications that process Adobe Portable Document Format files. The flaw specifically affects versions of xpdf, kpdf, and poppler libraries that handle PDF document structures according to Adobe PDF specification 1.3. The vulnerability stems from inadequate input validation and error handling mechanisms when processing malformed PDF catalog dictionaries or Pages attributes that reference invalid page tree nodes. These components fail to properly validate the structural integrity of PDF objects during parsing, creating potential attack vectors that can be exploited through carefully crafted malicious PDF documents.
The technical implementation of this vulnerability exploits the way these PDF libraries traverse and interpret document object structures. When encountering a crafted catalog dictionary or malformed Pages attribute, the parsing routines can fall into infinite loops or execute code in unintended memory locations. This occurs because the affected libraries lack proper bounds checking and validation of object references within the PDF file structure. The vulnerability manifests when the parser attempts to follow invalid page tree node references or processes corrupted catalog entries that create circular references or malformed data structures. The specific nature of the flaw allows attackers to craft PDF files that cause the parsing engine to enter infinite loops during object traversal or to execute arbitrary code through memory corruption vulnerabilities.
The operational impact of this vulnerability spans multiple security domains including denial of service, remote code execution, and memory corruption attacks. Remote attackers can exploit this weakness by delivering malicious PDF files to unsuspecting users or systems that process PDF documents, potentially leading to complete system compromise. The denial of service aspect can cause applications to consume excessive CPU resources or memory, rendering them unavailable to legitimate users. More critically, the potential for arbitrary code execution means that attackers could gain control of affected systems, particularly when these libraries are used in web browsers, email clients, or document viewers. The memory corruption aspect introduces additional risks including privilege escalation and information disclosure.
Mitigation strategies for this vulnerability require immediate patching of affected software components and implementation of defensive measures. System administrators should prioritize updating xpdf, kpdf, and poppler libraries to versions that address the parsing flaws, with kpdf requiring updates to version 3.5.5 or later. Organizations should implement PDF file validation and sandboxing techniques to prevent execution of potentially malicious documents in production environments. Network-based defenses including web application firewalls and content filtering systems can help block suspicious PDF files before they reach end-user systems. The vulnerability aligns with CWE-129 and CWE-131 categories related to improper input validation and buffer overflow conditions, and represents a significant concern under ATT&CK technique T1203 for exploitation of software vulnerabilities. Regular security assessments and vulnerability scanning should be conducted to identify systems running outdated versions of these libraries that may remain susceptible to similar parsing vulnerabilities.