CVE-2009-2518 in PowerPoint
Summary
by MITRE
Integer overflow in GDI+ in Microsoft Office XP SP3 allows remote attackers to execute arbitrary code via an Office document with a bitmap (aka BMP) image that triggers memory corruption, aka "Office BMP Integer Overflow Vulnerability."
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Analysis
by VulDB Data Team • 08/23/2021
The CVE-2009-2518 vulnerability represents a critical integer overflow flaw within the Graphics Device Interface Plus component of Microsoft Office XP Service Pack 3, specifically affecting how the software processes bitmap image files. This vulnerability exists in the image parsing logic where the application fails to properly validate integer values during bitmap processing, creating a scenario where maliciously crafted bitmap images can cause arithmetic overflow conditions. The flaw occurs when the application attempts to calculate memory allocation sizes based on malformed bitmap headers, leading to insufficient memory allocation that subsequently gets overwritten during image rendering operations.
The technical execution of this vulnerability leverages the inherent weakness in GDI+ handling of bitmap image metadata, particularly within the BITMAPINFOHEADER structure where integer values control memory allocation calculations. When a malicious bitmap file contains crafted width and height values that, when multiplied together, exceed the maximum value that can be represented by a 32-bit signed integer, the arithmetic overflow results in a negative or truncated value being used for memory allocation. This corrupted allocation size then leads to heap-based buffer overflows during subsequent image rendering operations, allowing attackers to overwrite adjacent memory locations with malicious code.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass a complete compromise of affected systems running Microsoft Office XP SP3. Attackers can exploit this weakness by embedding maliciously crafted bitmap images within Office documents such as Word or Excel files, which when opened trigger the vulnerable GDI+ processing path. The vulnerability affects systems where Office XP SP3 is installed, making it particularly dangerous in enterprise environments where legacy software remains in use. Successful exploitation can result in full system compromise, allowing attackers to execute arbitrary code with the privileges of the user running the vulnerable Office application, potentially leading to persistent backdoor access and lateral movement within network environments.
Mitigation strategies for this vulnerability require immediate patching of affected systems with Microsoft security updates, as the original vulnerability was addressed through proper integer overflow checking in the GDI+ bitmap processing routines. Organizations should implement strict document filtering policies to prevent execution of Office documents from untrusted sources, particularly those containing embedded image files. Network-based protections including email filtering and web proxies should be configured to block potentially malicious Office documents and bitmap files. Additionally, system hardening measures such as disabling automatic execution of Office documents from untrusted sources and implementing application whitelisting can provide additional defense layers. This vulnerability aligns with CWE-190, Integer Overflow or Wraparound, and maps to ATT&CK technique T1203, Exploitation for Client Execution, highlighting the importance of both endpoint protection and network-based defenses. The vulnerability also demonstrates the persistent risk of legacy software environments where patches may not be applied promptly, emphasizing the need for comprehensive vulnerability management programs that address both current and historical software risks.