CVE-2010-2643 in Evince
Summary
by MITRE
Integer overflow in the TFM font parser in the dvi-backend component in Evince 2.32 and earlier allows remote attackers to execute arbitrary code via a crafted font in conjunction with a DVI file that is processed by the thumbnailer.
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Analysis
by VulDB Data Team • 10/11/2021
The vulnerability identified as CVE-2010-2643 represents a critical integer overflow flaw within the dvi-backend component of Evince document viewer version 2.32 and earlier. This issue specifically affects the True Type Font (TFM) parser implementation that processes DVI files for thumbnail generation. The vulnerability arises from inadequate input validation and arithmetic overflow handling when processing font metrics data within TFM files. When a maliciously crafted DVI file containing oversized font metrics is processed by Evince's thumbnailer functionality, the integer overflow condition can lead to memory corruption that adversaries can potentially exploit to execute arbitrary code on the victim system.
The technical exploitation of this vulnerability occurs through a carefully constructed TFM font file that triggers an integer overflow during the parsing process. The dvi-backend component in Evince handles DVI file processing, including thumbnail generation for document previews, making this attack vector particularly dangerous as it can be triggered simply by opening a malicious DVI file. The integer overflow manifests when the parser attempts to calculate memory allocation sizes based on malformed font metrics data, leading to insufficient buffer allocation that results in memory corruption. This type of vulnerability is classified under CWE-190 as an integer overflow or wraparound, specifically affecting the memory management routines during font processing operations.
From an operational perspective, this vulnerability presents a significant risk to users who may inadvertently open malicious DVI files, particularly in environments where document sharing occurs frequently. The attack requires only that the victim process a specially crafted DVI file through Evince's thumbnailer function, which typically occurs automatically when documents are displayed in file managers or when applications attempt to generate previews. The remote exploitation aspect means that attackers can deliver malicious DVI files through various vectors including email attachments, web downloads, or file sharing platforms. The successful exploitation can result in complete system compromise, as the arbitrary code execution allows attackers to gain full control over the affected system.
The security implications extend beyond immediate code execution to include potential privilege escalation and persistence mechanisms that attackers can leverage. Organizations using Evince versions prior to 2.32 should consider this vulnerability as a high-priority threat, particularly in environments where document processing occurs frequently. The vulnerability aligns with ATT&CK technique T1068, which covers local privilege escalation through application vulnerabilities, and T1203, which covers exploitation of remote services. Mitigation strategies include immediate upgrading to Evince version 2.32.1 or later, implementing strict file validation policies for DVI files, and disabling thumbnail generation for untrusted documents. Additionally, system administrators should consider implementing sandboxing techniques for document processing and monitoring for unusual memory allocation patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper integer overflow protection in font parsing libraries and highlights the need for comprehensive input validation in document processing components.