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Rex-1.16.1
⭐ Starred 717 / Rex::Commands::Sync
Security Advisories (1)
CVE-2026-94140 (2026-10-21)

Rex versions through 1.16.1 for Perl accept an unknown SSH host key for remote rsync transfers because sync hardcodes StrictHostKeyChecking=no. Every remote branch of sync builds its ssh command with that option, for password authentication, for private-key authentication and for the fallback. The ssh options a caller sets through set_openssh_opt reach the OpenSSH transport but not this command, so there is no configuration that restores host key checking for the transfer. An attacker who can redirect the connection before the real host key is known presents their own and the transfer proceeds: under password authentication sync sends the connection password to that server, an upload writes the selected local files to it, and a download writes what it returns to the local destination.

NAME

Rex::Commands::Sync - Sync directories

DESCRIPTION

This module can sync directories between your Rex system and your servers without the need of rsync.

SYNOPSIS

use Rex::Commands::Sync;

task "prepare", "mysystem01", sub {
  # upload directory recursively to remote system.
  sync_up "/local/directory", "/remote/directory";

  sync_up "/local/directory", "/remote/directory", {
    # setting custom file permissions for every file
    files => {
      owner => "foo",
      group => "bar",
      mode  => 600,
    },
    # setting custom directory permissions for every directory
    directories => {
      owner => "foo",
      group => "bar",
      mode  => 700,
    },
    exclude => [ '*.tmp' ],
    parse_templates => TRUE|FALSE,
    on_change => sub {
     my (@files_changed) = @_;
    },
  };

  # download a directory recursively from the remote system to the local machine
  sync_down "/remote/directory", "/local/directory";
};