CVE-2026-64399
Description
A flaw was found in ksmbd. This vulnerability allows a remote attacker to overwrite data on a shared file system due to insufficient permission checks in the FSCTL_DUPLICATE_EXTENTS_TO_FILE function. Even if a share is configured as read-only or a client has limited write attributes, an attacker can still modify the destination file's data, leading to unauthorized data alteration.
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability,Access Control
Technical Impact: Gain Privileges or Assume Identity; Execute Unauthorized Code or Commands; Read Application Data; DoS: Crash, Exit, or Restart
An attacker will be able to gain access to any resources that are allowed by the extra privileges. Common results include executing code, disabling services, and reading restricted data. New weaknesses can be exposed because running with extra privileges, such as root or Administrator, can disable the normal security checks being performed by the operating system or surrounding environment. Other pre-existing weaknesses can turn into security vulnerabilities if they occur while operating at raised privileges.
Frequently Asked Questions
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