CVE-2009-0146 in CUPS
Summary
by MITRE
Multiple buffer overflows in the JBIG2 decoder in Xpdf 3.02pl2 and earlier, CUPS 1.3.9 and earlier, and other products allow remote attackers to cause a denial of service (crash) via a crafted PDF file, related to (1) JBIG2SymbolDict::setBitmap and (2) JBIG2Stream::readSymbolDictSeg.
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Analysis
by VulDB Data Team • 09/02/2019
The vulnerability identified as CVE-2009-0146 represents a critical security flaw affecting multiple PDF processing applications that utilize the JBIG2 image compression standard. This issue manifests as multiple buffer overflows within the JBIG2 decoder component, specifically impacting Xpdf version 3.02pl2 and earlier releases, as well as CUPS version 1.3.9 and earlier implementations. The flaw resides in the handling of JBIG2 encoded image data within PDF documents, creating a pathway for remote attackers to exploit the system through maliciously crafted PDF files. The vulnerability is particularly concerning because it affects widely deployed software components that process PDF documents, making it a prime target for exploitation in various attack scenarios.
The technical implementation of this vulnerability stems from improper bounds checking within the JBIG2 decoder's internal functions, specifically within the JBIG2SymbolDict::setBitmap and JBIG2Stream::readSymbolDictSeg methods. These functions fail to validate the size and structure of incoming JBIG2 data segments, allowing attackers to craft PDF files containing oversized or malformed JBIG2 symbol dictionary segments. When the affected software attempts to process these malicious segments, the buffer overflow occurs as the system attempts to copy data into memory buffers that are insufficiently sized to accommodate the crafted input. This results in memory corruption that ultimately leads to application termination and denial of service conditions, effectively rendering the affected systems unusable for PDF processing operations.
The operational impact of CVE-2009-0146 extends beyond simple denial of service, as it represents a fundamental flaw in input validation and memory management practices within PDF processing applications. Attackers can leverage this vulnerability to disrupt services by sending specially crafted PDF documents to systems running vulnerable versions of Xpdf, CUPS, or other affected software. The remote nature of the attack means that victims need not be physically present or have direct access to the target system, making it particularly dangerous in networked environments where PDF processing is common. This vulnerability directly aligns with CWE-121, which describes heap-based buffer overflow conditions, and demonstrates the critical importance of proper input validation in security-critical applications.
Organizations utilizing affected software should prioritize immediate remediation through patch updates from vendors, as the vulnerability presents a clear and present danger to system availability. The recommended mitigation strategy involves upgrading to patched versions of Xpdf, CUPS, and any other affected applications that incorporate updated JBIG2 decoder implementations with proper bounds checking. Security administrators should also implement network-based controls such as PDF content filtering and sandboxing mechanisms to reduce the attack surface while patches are deployed. Additionally, monitoring for suspicious PDF processing activities and implementing intrusion detection systems that can identify potential exploitation attempts will help in early detection and response to attacks leveraging this vulnerability. The ATT&CK framework categorizes this as a denial of service attack vector that can be used in conjunction with other techniques to compromise system availability and service integrity, making it a critical component of overall security posture management.