CVE-2026-54591
Description
A flaw was found in AsyncSSH, a Python package for SSHv2 protocol implementation. A malicious SSH server could exploit this vulnerability by sending specially crafted filenames containing directory traversal sequences to an AsyncSSH SCP client. This could allow the server to write arbitrary files to the client's filesystem, leading to unauthorized data modification or system disruption.
Statement
This Important flaw in AsyncSSH's SCP client allows a malicious SSH server to perform arbitrary file writes on the client's filesystem through directory traversal. This occurs when an AsyncSSH SCP client connects to a compromised or malicious server, enabling unauthorized data modification or system disruption on the client.
Mitigation
The core risk of this flaw is that the malicious server uses a path traversal trick to write files where it shouldn't on your client (like overwriting /etc/shadow or critical system binaries). By making the container's root filesystem read-only, you completely neutralize this attack. Even if the vulnerability is triggered, the container's kernel will block the unauthorized write attempt.
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