CVE-2012-4895 in SumatraPDF
Summary
by MITRE
Heap-based buffer overflow in SumatraPDF before 2.1 allows remote attackers to execute arbitrary code via a crafted PDF document, a different vulnerability than CVE-2012-4896.
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Analysis
by VulDB Data Team • 12/14/2021
The heap-based buffer overflow vulnerability identified as CVE-2012-4895 affects SumatraPDF versions prior to 2.1, representing a critical security flaw that enables remote code execution through maliciously crafted PDF documents. This vulnerability specifically targets the heap memory management mechanisms within the PDF rendering engine, creating a pathway for attackers to inject and execute arbitrary code on vulnerable systems. The flaw differs from CVE-2012-4896, indicating distinct code paths and exploitation vectors that require separate mitigation strategies.
This vulnerability resides in the heap memory allocation and management processes used by SumatraPDF when processing PDF files, particularly when handling malformed or specially crafted PDF content. The buffer overflow occurs during the parsing and rendering of PDF elements, where insufficient bounds checking allows attackers to write data beyond the allocated heap memory boundaries. The technical implementation involves improper memory management where the application fails to validate input lengths or buffer sizes before performing memory operations, leading to memory corruption that can be exploited to overwrite critical memory locations.
The operational impact of this vulnerability extends beyond simple remote code execution, as it allows attackers to gain full control over affected systems running vulnerable versions of SumatraPDF. An attacker can craft a malicious PDF document that, when opened by an unsuspecting user, triggers the buffer overflow condition and executes malicious payload code with the privileges of the running application. This creates a significant risk for users who frequently open PDF documents from untrusted sources, particularly in enterprise environments where PDF viewing is common. The vulnerability affects not only individual users but also organizations that rely on SumatraPDF for document viewing and processing.
Mitigation strategies for CVE-2012-4895 include immediate patching of SumatraPDF to version 2.1 or later, which contains the necessary memory validation fixes and heap management improvements. Organizations should implement strict PDF document filtering and scanning protocols to identify potentially malicious content before processing. Additionally, users should be educated about the risks of opening PDF documents from untrusted sources and encouraged to maintain updated software versions. The vulnerability aligns with CWE-122, which describes heap-based buffer overflow conditions, and maps to ATT&CK technique T1203, representing exploitation of software vulnerabilities for privilege escalation and code execution. Network-based mitigations such as web application firewalls and content filtering systems can provide additional protection layers while patches are deployed.