CVE-2019-10872 in Poppler
Summary
by MITRE
An issue was discovered in Poppler 0.74.0. There is a heap-based buffer over-read in the function Splash::blitTransparent at splash/Splash.cc.
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Analysis
by VulDB Data Team • 08/27/2023
The vulnerability identified as CVE-2019-10872 represents a critical heap-based buffer over-read flaw within the Poppler PDF rendering library version 0.74.0. This issue resides in the Splash graphics rendering component, specifically within the Splash::blitTransparent function located at splash/Splash.cc. The vulnerability manifests when the PDF renderer processes certain malformed or crafted PDF documents that contain specific graphical elements or transparency operations. Such buffer over-read conditions occur when the application attempts to read memory locations beyond the allocated buffer boundaries, potentially leading to information disclosure, application instability, or in severe cases, arbitrary code execution.
The technical nature of this vulnerability stems from inadequate bounds checking within the Splash::blitTransparent function which handles transparent bitmap operations during PDF rendering. When processing PDF files with malformed transparency data, the function fails to properly validate the size parameters of the source buffer before performing memory read operations. This flaw falls under the CWE-125 vulnerability category, which specifically addresses out-of-bounds read conditions in software implementations. The vulnerability is particularly concerning because it exists within a core rendering component that is widely used across various applications, from web browsers to document viewers, making it a prime target for exploitation in remote code execution scenarios.
The operational impact of CVE-2019-10872 extends beyond simple rendering failures, as it creates potential attack vectors for malicious actors seeking to compromise systems through PDF-based attacks. Attackers can craft specially designed PDF documents that trigger the buffer over-read condition when opened by vulnerable applications, potentially leading to system compromise. The vulnerability's exploitation risk is elevated by the widespread adoption of Poppler across multiple platforms and applications, including major browsers like Chrome and Firefox, as well as desktop PDF viewers such as Evince and Okular. This makes the attack surface significantly broader than typical library vulnerabilities, as any application leveraging Poppler for PDF rendering becomes a potential target.
Mitigation strategies for this vulnerability require immediate patching of affected Poppler installations to version 0.75.0 or later, which contains the necessary fixes for the buffer over-read condition. Organizations should also implement additional defensive measures such as restricting PDF file processing to trusted sources, implementing sandboxing techniques for PDF rendering operations, and monitoring for suspicious PDF file characteristics that might indicate crafted exploit attempts. The vulnerability aligns with several ATT&CK techniques including T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) as attackers may leverage this flaw to execute malicious code through PDF-based delivery mechanisms. Security teams should also consider implementing network-level filtering to block suspicious PDF content and ensure that all systems utilizing Poppler libraries are regularly updated to prevent exploitation attempts.