Critical Windows Graphics Vulnerabilities Expose Systems to Remote Code Execution
Recent discoveries have unveiled multiple critical vulnerabilities within Microsoft’s Graphics Device Interface (GDI), a fundamental component of the Windows operating system responsible for rendering graphics. These flaws, identified through an extensive fuzzing campaign targeting Enhanced Metafile (EMF) formats, pose significant security risks, potentially allowing remote attackers to execute arbitrary code or access sensitive data.
Understanding the Vulnerabilities
The identified vulnerabilities originate from improper handling of EMF+ records, which are utilized in documents and images processed by applications such as Microsoft Office and various web browsers. By crafting malicious files—like rigged Word documents or image thumbnails—attackers can exploit these flaws, leading to full system compromise without requiring user interaction.
Detailed Analysis of Key Vulnerabilities
1. CVE-2025-30388: This vulnerability, rated as Important with a CVSS score of 8.8, involves out-of-bounds memory operations during the processing of records like EmfPlusDrawString and EmfPlusFillRects. Triggered by malformed EmfPlusSetTSClip records, it allows attackers to read or write beyond allocated heap buffers, potentially leaking data or enabling code execution. This flaw affects Windows 10 and 11, as well as Office for Mac and Android. Microsoft has deemed it Exploitation More Likely due to its accessibility via common file formats.
2. CVE-2025-53766: Classified as Critical with a CVSS score of 9.8, this vulnerability permits remote code execution through out-of-bounds writes in the ScanOperation::AlphaDivide_sRGB function. By crafting EmfPlusDrawRects records with oversized rectangles, attackers can overflow scan-line buffers in bitmap rendering, bypassing boundaries in thumbnail generation. No privileges are required, making it ideal for network-based attacks on services parsing EMF files.
3. CVE-2025-47984: An Information Disclosure bug with a CVSS score of 7.5, this vulnerability exploits a lingering flaw in EMR_STARTDOC record handling, tied to an incomplete fix for CVE-2022-35837. It causes over-reads in string length calculations, exposing adjacent heap memory. Classified as a protection mechanism failure (CWE-693), this could aid further attacks by revealing system secrets.
Mitigation Measures
Microsoft has addressed these vulnerabilities in updates to GdiPlus.dll and gdi32full.dll, incorporating validations for rectangles, scan-lines, and offsets to prevent overflows. Users are strongly advised to apply these patches immediately and enable automatic updates to ensure ongoing protection.
In addition to applying patches, it is recommended to disable EMF rendering in untrusted contexts, utilize sandboxed viewers for documents, and monitor for anomalous graphics processing activities.
Broader Implications
These discoveries highlight the persistent challenges in securing deeply embedded system libraries. As remote work and cloud services continue to expand, such vulnerabilities pose escalating threats to enterprises. The findings underscore the importance of continuous security assessments and proactive patch management to safeguard systems against emerging threats.
