{"id":58375,"date":"2025-07-08T10:00:45","date_gmt":"2025-07-08T10:00:45","guid":{"rendered":""},"modified":"2025-09-27T15:20:30","modified_gmt":"2025-09-27T21:20:30","slug":"cve-2025-30376-heap-based-buffer-overflow-in-microsoft-office-excel-leading-to-potential-system-compromise","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-30376-heap-based-buffer-overflow-in-microsoft-office-excel-leading-to-potential-system-compromise\/","title":{"rendered":"CVE-2025-30376: Heap-based Buffer Overflow in Microsoft Office Excel Leading to Potential System Compromise<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

CVE-2025-30376 is a high severity vulnerability present in Microsoft Office Excel. This vulnerability stems from a heap-based buffer overflow that could potentially allow unauthorized attackers to execute code locally on the victim’s system. It poses a significant threat to the security of sensitive data, as it may permit system compromise<\/a> or data leakage.
\nThe vulnerability is of particular concern due<\/a> to the widespread usage of Microsoft Office Excel across industries and organizations of all sizes. The successful exploitation of this vulnerability could lead<\/a> to significant breaches, putting personal, financial, and business-critical information at risk.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-30376
\nSeverity: High – CVSS 7.8
\nAttack Vector: Local
\nPrivileges Required: None
\nUser Interaction: Required
\nImpact: Execution of unauthorized code<\/a> leading to potential system compromise or data leakage.<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

Microsoft Office<\/a> Excel | [Insert affected version]<\/p>\n

How the Exploit Works<\/strong><\/p>\n

The vulnerability arises from a heap-based buffer overflow in Microsoft Office<\/a> Excel. An attacker can exploit this by crafting a malicious Excel document that, when opened, overflows the buffer<\/a> and allows the attacker to execute arbitrary code. This code execution happens within the security context of the current user, which could lead to unauthorized system access or data leakage if the user possesses elevated privileges<\/a>.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

A conceptual exploit might involve a malicious macro embedded within an Excel document. Once the document is opened and the macro is executed, it can result in buffer overflow<\/a>. Here’s a concept of how this might look:<\/p>\n

Sub MaliciousMacro()\nDim buffer As String\nDim overflow As String\n' Fill the buffer with data\nbuffer = String(1, \"A\")\n' Create an overflow string longer than the buffer can handle\noverflow = String(2, \"B\")\n' Cause the buffer overflow, leading to potential arbitrary code execution\nbuffer = overflow\nEnd Sub<\/code><\/pre>\n
Mitigation Guidance<\/strong><\/p>\n
Users are advised to apply the vendor patch as soon as it becomes available for their version of Microsoft Office<\/a> Excel. As a temporary mitigation strategy, deploying a Web<\/a> Application Firewall (WAF) or Intrusion Detection System (IDS) can help detect and prevent exploitation attempts. Additionally, it is recommended to exercise caution when opening Excel documents from untrusted sources<\/a> and to disable macros by default.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview CVE-2025-30376 is a high severity vulnerability present in Microsoft Office Excel. This vulnerability stems from a heap-based buffer overflow that could potentially allow unauthorized attackers to execute code locally on the victim’s system. It poses a significant threat to the security of sensitive data, as it may permit system compromise or data leakage. The […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[1],"tags":[],"vendor":[82],"product":[],"attack_vector":[86,80],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-58375","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-microsoft","attack_vector-buffer-overflow","attack_vector-rce"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t