CVE-2009-0195 in Xpdf
Summary
by MITRE
Heap-based buffer overflow in Xpdf 3.02pl2 and earlier, CUPS 1.3.9, and probably other products, allows remote attackers to execute arbitrary code via a PDF file with crafted JBIG2 symbol dictionary segments.
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Analysis
by VulDB Data Team • 08/09/2021
The vulnerability identified as CVE-2009-0195 represents a critical heap-based buffer overflow affecting multiple PDF processing libraries and print systems. This flaw exists within the handling of JBIG2 symbol dictionary segments in PDF files, specifically impacting Xpdf version 3.02pl2 and earlier releases as well as CUPS 1.3.9. The vulnerability stems from inadequate input validation and bounds checking when processing malformed JBIG2 compressed data structures within PDF documents. Attackers can exploit this weakness by crafting malicious PDF files containing specially constructed JBIG2 symbol dictionary segments that trigger memory corruption during the decompression process.
The technical implementation of this vulnerability resides in the heap memory management of PDF rendering engines that process JBIG2 compression standards. When the affected software encounters a malformed JBIG2 symbol dictionary segment, the parser fails to properly validate the size parameters or memory allocation limits before copying data into heap buffers. This leads to a classic heap overflow condition where adjacent memory regions become overwritten with attacker-controlled data. The vulnerability maps to CWE-121 Heap-based Buffer Overflow, which is classified as a fundamental memory safety issue that allows arbitrary code execution through memory corruption. The attack vector is remote and requires no authentication, making it particularly dangerous in environments where users might encounter untrusted PDF documents.
The operational impact of CVE-2009-0195 extends across multiple system components and deployment scenarios. Systems utilizing affected versions of Xpdf for PDF rendering, CUPS for print spooling, or any other software incorporating vulnerable JBIG2 decompression libraries become susceptible to remote code execution. This vulnerability affects web browsers, PDF viewers, print servers, and document processing systems that handle JBIG2 compressed content. The attack can result in complete system compromise, allowing threat actors to execute malicious code with the privileges of the affected application. This represents a significant concern for enterprise environments where PDF processing is common, as it can serve as an initial access vector for broader network infiltration.
Security mitigations for this vulnerability require immediate patching of affected software components to address the buffer overflow in JBIG2 decompression routines. Organizations should implement comprehensive software inventory management to identify all systems running vulnerable versions of Xpdf, CUPS, or related libraries. Network-based defenses should include PDF content filtering and sandboxing mechanisms to prevent execution of potentially malicious documents. The vulnerability aligns with ATT&CK technique T1203 Exploitation for Client Execution, where adversaries leverage software vulnerabilities to execute arbitrary code on target systems. Regular security updates and vulnerability assessments should be implemented to prevent similar issues in other compression standards and PDF processing components. System administrators should also consider implementing least privilege principles for PDF processing applications and monitor for unusual network activity that might indicate exploitation attempts.