CVE-2009-0756 in Poppler
Summary
by MITRE
The JBIG2Stream::readSymbolDictSeg function in Poppler before 0.10.4 allows remote attackers to cause a denial of service (crash) via a PDF file that triggers a parsing error, which is not properly handled by JBIG2SymbolDict::~JBIG2SymbolDict and triggers an invalid memory dereference.
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Analysis
by VulDB Data Team • 12/15/2024
The vulnerability identified as CVE-2009-0756 represents a critical denial of service flaw within the Poppler PDF rendering library version 0.10.3 and earlier. This issue specifically affects the JBIG2Stream::readSymbolDictSeg function which processes JBIG2 compression data within PDF documents. The flaw occurs when a maliciously crafted PDF file contains malformed JBIG2 data that triggers a parsing error during the symbol dictionary segment processing. The vulnerability stems from inadequate error handling mechanisms within the JBIG2SymbolDict destructor function, which fails to properly manage memory cleanup when parsing errors occur. This improper error handling leads to an invalid memory dereference condition that causes the application to crash.
The technical exploitation of this vulnerability requires an attacker to craft a PDF file containing specifically malformed JBIG2 compression data that will trigger the parsing error path within the Poppler library. When the affected library attempts to process such a document, the JBIG2Stream::readSymbolDictSeg function encounters a parsing error that is not properly caught and handled. Subsequently, when the JBIG2SymbolDict destructor is called during cleanup, it attempts to access memory that has already been freed or is otherwise invalid, resulting in a memory dereference violation. This type of vulnerability falls under the CWE-476 category of NULL Pointer Dereference, though it specifically manifests as an invalid memory dereference due to improper cleanup handling.
The operational impact of CVE-2009-0756 extends beyond simple service disruption as it can be leveraged in various attack scenarios. Web applications that utilize Poppler for PDF processing or rendering become vulnerable to remote exploitation, allowing attackers to crash services simply by providing a malicious PDF file. This vulnerability is particularly concerning in environments where PDF processing is automated or where users can upload documents, as it can be used to perform denial of service attacks against web applications, print servers, or document processing systems. The flaw affects not only end-user applications but also server-side PDF processing services that may be exposed to untrusted input, creating potential for widespread service disruption.
Organizations should implement immediate mitigations by upgrading to Poppler version 0.10.4 or later, which contains the necessary fixes to properly handle parsing errors and memory cleanup during JBIG2 data processing. System administrators should also consider implementing input validation measures that filter or reject PDF files containing JBIG2 compression data where possible, particularly in high-risk environments. The ATT&CK framework categorizes this vulnerability under the T1499.004 technique for Network Denial of Service, as it allows attackers to consume system resources through invalid memory access patterns. Additional defensive measures include deploying sandboxing mechanisms for PDF processing and implementing strict access controls for PDF handling services to limit the potential impact of exploitation.