CVE-2007-5746 in OpenOffice
Summary
by MITRE
Integer overflow in OpenOffice.org before 2.4 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via an EMF file with a crafted EMR_STRETCHBLT record, which triggers a heap-based buffer overflow.
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Analysis
by VulDB Data Team • 08/09/2019
The vulnerability identified as CVE-2007-5746 represents a critical integer overflow flaw within OpenOffice.org versions prior to 2.4 that enables remote attackers to manipulate the application through specially crafted EMF (Enhanced Metafile) files. This vulnerability specifically targets the EMR_STRETCHBLT record within EMF file formats, which are used for vector graphics and graphics device interface operations in Windows environments. The flaw occurs during the processing of these records when the application fails to properly validate integer values, leading to arithmetic overflow conditions that can result in heap-based buffer overflows.
The technical implementation of this vulnerability exploits the way OpenOffice.org handles graphic rendering operations by processing EMF files that contain maliciously constructed EMR_STRETCHBLT records. When the application encounters these crafted records, the integer overflow condition causes the application to allocate insufficient memory for buffer operations, resulting in memory corruption that manifests as heap corruption. This type of vulnerability falls under the CWE-190 category of Integer Overflow or Wraparound, which is classified as a fundamental weakness in software design that allows attackers to manipulate integer values beyond their intended range. The vulnerability's classification aligns with ATT&CK technique T1203 which involves the exploitation of memory corruption vulnerabilities to execute arbitrary code or cause system instability.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution in targeted environments. When an attacker successfully triggers this vulnerability through a malicious EMF file, the application crashes due to the heap corruption, but in some cases, the corrupted memory state may allow for code execution within the application's context. This represents a significant security risk for organizations that process untrusted document files, particularly in environments where users may inadvertently open malicious attachments or visit compromised websites that deliver these crafted EMF files. The vulnerability affects the core document processing capabilities of OpenOffice.org, making it a critical concern for users who rely on the application for document handling and office productivity tasks.
Mitigation strategies for CVE-2007-5746 primarily focus on immediate patching and application updates to OpenOffice.org version 2.4 or later, which contains the necessary fixes for the integer overflow conditions in EMF file processing. Organizations should implement strict file validation policies that prevent automatic opening of untrusted EMF files, particularly in enterprise environments where users may encounter malicious attachments. Network-level defenses such as email filtering and web proxy configurations should be enhanced to detect and block EMF file attachments from untrusted sources. Additionally, system administrators should consider implementing application whitelisting policies that restrict the execution of vulnerable applications or ensure that only patched versions of OpenOffice.org are deployed in organizational environments. The vulnerability demonstrates the importance of proper input validation and integer overflow protection in graphics processing libraries, highlighting the need for robust memory management practices in software applications that handle external file formats and user-supplied data.