CVE-2012-4337 in Foxit
Summary
by MITRE
Foxit Reader before 5.3 on Windows XP and Windows 7 allows remote attackers to execute arbitrary code via a PDF document with a crafted attachment that triggers calculation of a negative number during processing of cross references.
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Analysis
by VulDB Data Team • 12/30/2024
The vulnerability identified as CVE-2012-4337 represents a critical buffer overflow condition within Foxit Reader version 5.2 and earlier, specifically affecting Windows XP and Windows 7 operating systems. This security flaw resides in the PDF processing engine's handling of cross-reference calculations, where maliciously crafted PDF attachments can trigger arithmetic operations resulting in negative values that subsequently lead to memory corruption. The vulnerability stems from inadequate input validation and boundary checking during the parsing of PDF cross-reference tables, which are essential components that map object locations within PDF files. When the reader encounters a crafted negative value during cross-reference processing, it fails to properly validate the calculated offset, creating an exploitable condition that allows attackers to manipulate memory layout and execute arbitrary code with the privileges of the affected user.
The technical implementation of this vulnerability demonstrates a classic integer underflow scenario that falls under CWE-191, which specifically addresses integer underflows or wrapping in signed integer types. The flaw occurs during the processing of PDF cross-reference streams where the application performs calculations that should result in positive offsets within the file structure. However, when attackers manipulate the PDF content to force negative arithmetic results during cross-reference calculation, the application's memory management routines become compromised. This condition creates a scenario where the application attempts to access memory locations that are either invalid or controlled by the attacker, providing a pathway for code execution. The vulnerability is particularly dangerous because it requires no user interaction beyond opening the malicious PDF document, making it a prime candidate for drive-by download attacks and social engineering campaigns. The attack vector operates through the standard PDF rendering pipeline where the malicious attachment is processed without user intervention, exploiting the reader's trust in PDF file structures.
The operational impact of CVE-2012-4337 extends beyond simple code execution to encompass complete system compromise, as the vulnerability can be leveraged for privilege escalation and persistent access within targeted environments. Attackers can craft PDF documents that exploit this condition to inject malicious code into the reader's memory space, potentially bypassing standard security controls such as address space layout randomization and data execution prevention mechanisms. The vulnerability affects organizations heavily reliant on PDF document processing, particularly those in financial services, healthcare, and government sectors where document security is paramount. Security researchers have documented numerous real-world exploitation attempts targeting enterprise networks, where the vulnerability was used to establish initial access points for more sophisticated attack chains. The low complexity of exploitation combined with high impact makes this vulnerability particularly attractive to both automated attack tools and advanced persistent threat actors, as it provides reliable code execution without requiring complex exploitation techniques.
Mitigation strategies for CVE-2012-4337 primarily focus on immediate software updates and operational security measures. Organizations should prioritize updating Foxit Reader to version 5.3 or later, which includes patches addressing the cross-reference calculation vulnerability. System administrators should implement network-based controls such as PDF content filtering and sandboxing solutions to prevent potentially malicious documents from reaching end users. The implementation of principle of least privilege access controls and regular security assessments can help reduce the impact of successful exploitation attempts. Additionally, user education programs should emphasize the dangers of opening unexpected PDF attachments and encourage verification of document sources before processing. From a defensive perspective, security monitoring should include detection of anomalous PDF processing behavior and memory access patterns that may indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1203, which covers Exploitation for Client Execution, and represents a common pathway for initial access in enterprise security breaches. Organizations should also consider implementing web application firewalls and content inspection systems that can identify and block malicious PDF content before it reaches vulnerable systems. Regular vulnerability scanning and penetration testing can help identify systems running unpatched versions of Foxit Reader, while incident response procedures should include specific protocols for handling PDF-based attack vectors and memory corruption exploits.