好的，我现在需要帮用户总结一篇关于Windows Cloud Files Mini Filter Driver漏洞的文章，控制在100字以内。首先，我要通读整篇文章，抓住关键点。 文章开头提到发现了CVE-2025-55680漏洞，这是一个关键的权限提升漏洞。接着，它利用TOCTOU漏洞绕过文件写入限制，让本地攻击者获得系统级访问权限。技术细节部分说明这个漏洞源于2020年Project Zero的一个披露，当时试图防止符号链接攻击，但后来被发现存在时间窗口问题。 攻击者可以在安全检查和实际文件操作之间修改内存，绕过所有保护。利用链涉及Cloud Files API的几个函数，最终导致在受保护的系统目录中创建文件，并以内核模式访问权限运行。这允许任意DLL注入到系统进程中。 攻击分为四步：注册同步根、创建目录连接、建立通信端口、创建线程竞争提交请求和修改内存缓冲区。最后，恶意DLL通过RPC调用加载到特权服务中完成权限提升。 补丁状态是可用的，微软已经发布了修复程序，组织应立即部署。威胁级别高，因为有详细的exploit代码公开。 总结时要涵盖漏洞名称、类型、影响、攻击方式和补丁情况。控制在100字以内，避免使用“文章内容总结”等开头语。 </think> Windows Cloud Files Mini Filter Driver被发现存在关键权限提升漏洞（CVE-2025-55680），利用TOCTOU机制绕过文件写入限制，允许本地攻击者获取系统级访问权限。该漏洞源于2020年Project Zero披露的安全措施缺陷，在用户空间验证路径后未及时阻止内存修改，导致恶意DLL注入系统进程并完成提权。微软已发布补丁修复该问题。 2025-11-5 14:23:39 Author: cyberpress.org(查看原文) 阅读量:0 收藏
A critical privilege escalation vulnerability has been discovered in Windows Cloud Files Mini Filter Driver, designated as CVE-2025-55680.
The flaw leverages a time-of-check to time-of-use (TOCTOU) vulnerability to bypass file write restrictions, enabling local attackers to achieve unauthorized system-level access.
Technical Vulnerability Details
The vulnerability originates from a previous 2020 Project Zero disclosure that attempted to prevent symbolic link attacks by rejecting paths containing backslashes and colons.
However, researchers discovered that the path string validation occurs in user space before kernel-mode processing, creating a critical window of opportunity.
An attacker can modify memory between the security check and the actual file operation, bypassing all protections.
The exploitation chain involves the Cloud Files API function HsmFltProcessHSMControl, which calls HsmFltProcessCreatePlaceholders, ultimately reaching HsmpOpCreatePlaceholders.
When a path passes initial validation but gets swapped to a symbolic link target during the kernel call, the system creates files in protected system directories with kernel-mode access privileges.
This allows arbitrary DLL injection into system processes like the RAS service.
The attack unfolds through four precise steps. First, attackers register a Cloud Files sync root and create directory junctions pointing to system locations.
Second, they establish communication ports with the Cloud Files filter driver.
Third, they spawn threads that continuously race between submitting placeholder creation requests and modifying memory buffers to swap legitimate paths with symlink targets.
Finally, once a malicious DLL lands in system directories, it leverages RPC calls to force privileged services to load the compromised code, completing the privilege escalation.
| Attribute | Details |
|---|---|
| CVE ID | CVE-2025-55680 |
| Vulnerability Type | Privilege Escalation |
| Affected Component | Windows Cloud Files Mini Filter Driver |
| CVSS v3.1 Score | 7.8 High |
| Attack Vector | Local |
| Impact | Complete System Compromise |
| Patch Status | Available |
Microsoft has released patches addressing this vulnerability through its standard update channels. Organizations should prioritize deploying these patches immediately, as the attack requires only local system access and no user interaction.
The threat level remains significant given the direct path to system-level privileges and the public availability of detailed exploit code from the TyphoonPWN competition winner.
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Any Priya is a cybersecurity reporter at Cyber Press, specializing in cyber attacks, dark web monitoring, data breaches, vulnerabilities, and malware. She delivers in-depth analysis on emerging threats and digital security trends.
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