CVE-2019-14289 in Xpdf
Summary
by MITRE
An issue was discovered in Xpdf 4.01.01. There is an integer overflow in the function JBIG2Bitmap::combine at JBIG2Stream.cc for the "multiple bytes per line" case.
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Analysis
by VulDB Data Team • 11/13/2023
The vulnerability CVE-2019-14289 represents a critical integer overflow flaw within the Xpdf 4.01.01 PDF rendering library that affects the JBIG2Bitmap::combine function in JBIG2Stream.cc. This issue occurs specifically in the "multiple bytes per line" processing path, where the software fails to properly validate integer arithmetic operations that could lead to unexpected behavior during image decompression. The flaw exists in the handling of JBIG2 compressed image data within PDF documents, making it particularly dangerous in environments where PDF processing is prevalent. Such vulnerabilities in PDF libraries can have far-reaching implications as they may be exploited by attackers to compromise systems through malicious document delivery.
The technical root cause of this vulnerability stems from improper integer overflow checking within the JBIG2 image processing pipeline. When the JBIG2Bitmap::combine function processes images with multiple bytes per line, it performs arithmetic operations that can exceed the maximum representable value for signed integers. This overflow condition results in incorrect memory allocation calculations or buffer size determinations that can lead to memory corruption. The vulnerability manifests when the software attempts to compute line sizes or buffer allocations based on parameters that have been manipulated to trigger the overflow condition, potentially causing the application to allocate insufficient memory or attempt to access invalid memory regions. This type of vulnerability is classified under CWE-190 as an integer overflow or wraparound, which is a well-documented weakness in software security.
The operational impact of CVE-2019-14289 extends beyond simple denial of service scenarios, as it can potentially enable remote code execution in affected systems. When exploited, this vulnerability allows attackers to craft malicious PDF documents that, when processed by vulnerable Xpdf implementations, can trigger memory corruption and arbitrary code execution. The attack surface includes any application or system that relies on Xpdf for PDF rendering, including web browsers with embedded PDF viewers, document management systems, and security scanning tools. The vulnerability is particularly concerning because JBIG2 compression is commonly used in PDF documents, especially in government and financial sectors where document integrity is paramount. The flaw can be leveraged in phishing campaigns, supply chain attacks, or targeted intrusion attempts where attackers deliver malicious PDFs designed to exploit this specific integer overflow condition.
Organizations using Xpdf 4.01.01 or earlier versions should immediately implement mitigations to address this vulnerability. The primary solution involves upgrading to a patched version of Xpdf that properly handles integer overflow conditions in the JBIG2 processing code. Security teams should also consider implementing additional protective measures such as PDF document sanitization, restricted PDF processing in sandboxed environments, and network-based filtering of suspicious PDF content. The ATT&CK framework categorizes this vulnerability under T1203 as Exploitation for Client Execution, highlighting the potential for attackers to execute code through compromised PDF processing applications. Organizations should also monitor for indicators of compromise related to PDF processing activities and implement robust patch management procedures to prevent exploitation of this and similar vulnerabilities in their software ecosystems.