CVE-2022-28787 in wmfextractor
Summary
by MITRE • 05/04/2022
Improper buffer size check logic in wmfextractor library prior to SMR May-2022 Release 1 allows out of bounds read leading to possible temporary denial of service. The patch adds buffer size check logic.
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Analysis
by VulDB Data Team • 05/07/2022
The vulnerability identified as CVE-2022-28787 affects the wmfextractor library, a component commonly used for processing Windows Metafile format files within various software applications. This issue represents a classic buffer overflow condition that occurs when the library fails to properly validate the size of input data before processing. The vulnerability specifically manifests in versions of the library prior to the SMR May-2022 Release 1 patch, indicating that it was a known issue that required immediate attention from software vendors and system administrators. The flaw exists in the buffer size check logic, which is fundamental to preventing memory corruption during file processing operations.
The technical implementation of this vulnerability stems from inadequate input validation mechanisms within the wmfextractor library. When processing WMF files, the library reads data into buffers without properly verifying that the incoming data conforms to expected size parameters. This oversight creates a condition where an attacker can craft malicious WMF files that contain oversized data structures, causing the library to read beyond allocated memory boundaries. The out of bounds read operation can occur when the library attempts to access memory locations that were not properly allocated for the buffer, potentially leading to memory corruption and unpredictable behavior. This type of vulnerability falls under CWE-129, which specifically addresses improper validation of the length of input data, and represents a subset of buffer overflow vulnerabilities that can lead to denial of service conditions.
The operational impact of CVE-2022-28787 extends beyond simple temporary denial of service, as it can potentially be exploited to cause more severe system instability or even enable further attack vectors. When an out of bounds read occurs, the system may experience application crashes, unexpected behavior, or complete service interruption, depending on how the library is integrated into the target application. The vulnerability affects any system that relies on the wmfextractor library for WMF file processing, including email servers, document management systems, and various productivity applications that handle graphic file formats. From an attacker perspective, this vulnerability can be leveraged to create persistent denial of service conditions, as repeated exploitation can keep systems in a non-functional state until manual intervention occurs. The ATT&CK framework categorizes this type of vulnerability under T1499.004, which covers the use of network denial of service techniques, though it's important to note that the vulnerability itself is more accurately classified as a software defect rather than an active attack vector.
Mitigation strategies for CVE-2022-28787 primarily focus on updating affected systems to versions that include the SMR May-2022 Release 1 patch or later. System administrators should conduct comprehensive inventory audits to identify all installations of the affected wmfextractor library and prioritize patch deployment across critical systems. Additionally, implementing input validation measures at the application level can provide defense in depth, ensuring that even if the library itself is not patched, malicious input can be rejected before reaching the vulnerable component. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of exploitation, particularly in environments where WMF files are processed automatically. The patch implementation should be followed by thorough regression testing to ensure that legitimate functionality remains intact while the vulnerability is addressed. Security monitoring should be enhanced to detect potential exploitation attempts, including unusual patterns of WMF file processing or system resource consumption that might indicate denial of service conditions.