CVE-2025-49697 in Office
Summary
by MITRE • 07/08/2025
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
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Analysis
by VulDB Data Team • 06/29/2026
A heap-based buffer overflow vulnerability exists within Microsoft Office applications that enables remote code execution by malicious actors who have gained unauthorized access to a target system. This critical security flaw stems from improper input validation and memory management practices within the office suite's processing routines, particularly when handling specially crafted documents or files that trigger memory corruption during parsing operations. The vulnerability manifests when the application attempts to write data beyond the allocated heap memory boundaries, creating opportunities for attackers to manipulate program execution flow through carefully constructed malicious payloads.
The technical nature of this flaw aligns with common weakness enumeration CWE-121 which describes heap-based buffer overflows occurring when insufficient bounds checking allows writes to exceed allocated memory regions. This vulnerability type specifically targets heap memory management structures where applications dynamically allocate and deallocate memory blocks during runtime operations. Attackers exploit this condition by crafting malicious Office documents that, when opened by vulnerable versions of Microsoft Office, trigger the buffer overflow during document parsing. The corrupted heap memory can then be manipulated to overwrite critical program pointers or function return addresses, enabling arbitrary code execution with the privileges of the targeted user account.
The operational impact of this vulnerability extends beyond simple local privilege escalation scenarios, as it provides attackers with persistent access to target systems through legitimate Office application interfaces. Once exploited, adversaries can execute malicious code that may install additional malware, establish backdoors, or exfiltrate sensitive data from compromised environments. The attack surface is particularly concerning given Microsoft Office's widespread deployment across enterprise networks and its integration with various file sharing protocols and email clients. Security researchers have identified that successful exploitation often requires minimal user interaction beyond opening the malicious document, making this vulnerability particularly dangerous in phishing campaigns or social engineering attacks.
Mitigation strategies for this heap-based buffer overflow vulnerability encompass multiple layers of defensive measures including immediate patch deployment from Microsoft security updates, application whitelisting implementations to restrict execution of untrusted Office documents, and network segmentation controls to limit lateral movement. Organizations should also implement robust email filtering solutions that can identify and quarantine suspicious Office documents before they reach end users. The use of exploit protection features such as data execution prevention and address space layout randomization can significantly reduce exploitation success rates even when patches are not immediately available. Security teams must monitor for indicators of compromise including unusual network connections or file access patterns that may suggest exploitation attempts, while maintaining detailed audit logs of Office application usage to detect potential unauthorized access attempts. Compliance with industry standards such as those outlined in the mitre ATT&CK framework's technique T1204.002 for legitimate credentials and T1059.001 for command and scripting interpreter can help security professionals better understand and respond to exploitation patterns associated with this vulnerability class.