CVE-2026-104805: Mitel MiVoice Office 400 Backup Restoration Arbitrary File Write Leading to Root Code Execution
DigitalCanion has discovered a vulnerability in the backup restoration functionality that allows an attacker with access to the configured backup repository to introduce arbitrary files into the system during restoration.
The specific flaw exists within the backup restoration mechanism, which fails to properly validate the paths, file types, integrity, and authenticity of files contained within a restored TGZ archive. The application does not perform file-signature verification before extracting the archive, allowing a specially crafted backup to contain attacker-controlled files.
An attacker with access to the backup SFTP or other configured repository can therefore provide a malicious TGZ archive that, when restored by the system, may place arbitrary files on the underlying Linux system. Depending on the location and permissions of the extracted files, this behavior can potentially be leveraged to achieve arbitrary code execution with root privileges and compromise the underlying virtual machine.
The absence of enforced backup passwords further reduces the protection provided by the backup mechanism and may facilitate unauthorized access to the repository.
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
Deployments that restore backups from an SFTP or other configured backup repository are exposed if an attacker can access that repository and supply a malicious TGZ archive.
What must an attacker do to exploit the flaw?
The attacker needs access to the configured backup repository and must place a specially crafted backup archive there. Exploitation occurs when the system restores that archive.
Why can restoring a malicious backup lead to code execution?
The restoration process does not properly validate archive paths, file types, integrity, or authenticity, and does not verify file signatures before extraction. This can allow attacker-controlled files to be written to the underlying Linux system, potentially enabling root-level code execution depending on their extraction location and permissions.
Does the backup mechanism require passwords to protect repository access?
The available information states that backup passwords are not enforced. This reduces the protection of the backup mechanism and may make unauthorized repository access easier.