CVE-2026-4147 in Server
Summary
by MITRE • 03/17/2026
An authenticated user with the read role may read limited amounts of uninitialized stack memory via specially-crafted issuances of the filemd5 command.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/21/2026
This vulnerability resides in a system where authenticated users with read privileges can potentially access uninitialized stack memory through crafted filemd5 command executions. The flaw represents a classic information disclosure vulnerability that leverages the improper handling of memory allocation within the command processing mechanism. When a user issues the filemd5 command with specific parameters, the system fails to properly initialize stack variables before using them, creating an opportunity for sensitive data from adjacent memory locations to be exposed. This type of vulnerability falls under the category of information exposure through uninitialized memory access, which is commonly categorized as CWE-457: Use of Uninitialized Variable. The attack vector requires authentication and specifically targets the filemd5 functionality, making it a targeted privilege escalation concern rather than a broad system compromise.
The technical implementation of this vulnerability involves the stack memory management during command processing where the system does not adequately clear or initialize memory locations before storing command parameters or intermediate results. When the filemd5 command executes, it likely allocates memory on the stack for processing file checksums, but fails to properly initialize all memory regions. This allows adjacent stack data, potentially containing previously processed information, session tokens, or other sensitive data, to be inadvertently exposed through the command output. The vulnerability is particularly concerning because it requires only read privileges, meaning that even users with minimal access can potentially extract information from the system's memory space. The limited scope of uninitialized memory reading suggests that the exposure is constrained to small memory segments rather than extensive data leaks.
From an operational impact perspective, this vulnerability creates a significant risk for systems where filemd5 is frequently used and where sensitive information might be present in the stack memory during command execution. The exposure of uninitialized memory can potentially reveal session identifiers, cryptographic keys, user credentials, or other sensitive data that was previously stored in adjacent memory locations. This information disclosure could enable attackers to perform further attacks such as session hijacking, credential reuse, or privilege escalation within the system. The vulnerability aligns with ATT&CK technique T1005: Data from Local System, where adversaries can extract sensitive information from memory. The impact is particularly severe in environments where the system processes sensitive files or maintains authentication tokens in memory during command execution, as the uninitialized memory exposure could provide attackers with access to critical system information.
Mitigation strategies should focus on implementing proper memory initialization practices throughout the command processing pipeline, particularly for the filemd5 functionality. The system should ensure that all stack variables are properly initialized before use, preventing the accidental exposure of uninitialized memory contents. Additionally, input validation and sanitization should be enhanced to prevent attackers from manipulating command parameters in ways that could exacerbate the memory exposure. Security patches should include comprehensive memory management reviews to identify and address similar issues across other command processing functions. Organizations should also implement monitoring for unusual filemd5 command usage patterns and consider restricting access to this functionality to users who require it for legitimate purposes only. The remediation aligns with security best practices outlined in CWE guidelines for preventing uninitialized memory access and should be prioritized as a medium to high severity issue based on the potential for information disclosure and subsequent attack vectors that could be enabled by this vulnerability.