{"id":58442,"date":"2025-07-08T16:03:49","date_gmt":"2025-07-08T16:03:49","guid":{"rendered":""},"modified":"2025-10-07T18:13:45","modified_gmt":"2025-10-08T00:13:45","slug":"cve-2025-30381-a-critical-out-of-bounds-read-vulnerability-in-microsoft-office-excel","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-30381-a-critical-out-of-bounds-read-vulnerability-in-microsoft-office-excel\/","title":{"rendered":"CVE-2025-30381: A Critical Out-of-bounds Read Vulnerability in Microsoft Office Excel<\/strong>"},"content":{"rendered":"

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

CVE-2025-30381 is a significant cybersecurity vulnerability that affects Microsoft Office Excel, a widely used spreadsheet program. This vulnerability could allow an unauthorized attacker to execute code locally, potentially leading to system compromise or data leakage. As such, it poses a substantial threat to any organization or individual using affected versions of Microsoft Office<\/a> Excel. The severity of this vulnerability<\/a> is accentuated by its potential impacts, which range from unauthorized data access to full system compromise.<\/p>\n

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

CVE ID: CVE-2025-30381
\nSeverity: High – CVSS Score 7.8
\nAttack Vector: Local
\nPrivileges Required: None
\nUser Interaction: Required
\nImpact: Potential system<\/a> compromise or data leakage<\/p>\n

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

Product | Affected Versions<\/p>\n

Microsoft Office<\/a> Excel | All versions prior to the latest patch<\/p>\n

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

At its core, CVE-2025-30381 is an out-of-bounds read vulnerability<\/a>. This means that the software improperly verifies or handles data<\/a> within its buffer boundaries. In this case, an attacker can exploit<\/a> this flaw by tricking a user into opening a specially crafted Excel document that contains malicious code. When the affected software reads beyond the allocated buffer, it can cause the software to crash, potentially executing the attacker’s code<\/a> in the process.<\/p>\n

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

Consider the following conceptual Excel macro that represents how the vulnerability<\/a> might be exploited. This is a hypothetical example and does not represent an actual exploit:<\/p>\n

Sub MaliciousMacro()\nDim buffer(10) As Integer\nDim counter As Integer\n' Fill the buffer with innocent data\nFor counter = 0 To 10\nbuffer(counter) = counter\nNext counter\n' Overflow the buffer\nFor counter = 0 To 11\nbuffer(counter) = counter ' This line causes out-of-bounds read\nNext counter\n' Execute malicious code after the crash\nShell(\"malicious_command\")\nEnd Sub<\/code><\/pre>\n
This example illustrates how a malicious actor could craft a macro to cause an out-of-bounds read, leading to potential code execution<\/a>. It’s important to note that this is a conceptual example-actual exploit code would be more complex and designed<\/a> to evade detection.<\/p>\n
Mitigation Guidance<\/strong><\/p>\n
To protect against this vulnerability, it is recommended to apply the latest patches provided by Microsoft for Office<\/a> Excel. As a temporary mitigation, users can employ a Web Application<\/a> Firewall (WAF) or Intrusion Detection System (IDS). These systems can help detect and prevent malicious attempts to exploit this vulnerability<\/a>. However, they are not a substitute for applying the necessary patches and ensuring your software is up-to-date.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview CVE-2025-30381 is a significant cybersecurity vulnerability that affects Microsoft Office Excel, a widely used spreadsheet program. This vulnerability could allow an unauthorized attacker to execute code locally, potentially leading to system compromise or data leakage. As such, it poses a substantial threat to any organization or individual using affected versions of Microsoft Office Excel. […]<\/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":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-58442","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-microsoft"],"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