Description
kas is a setup tool for bitbake based projects. Prior to 5.4, internal SSH key setup triggered by SSH_PRIVATE_KEY or SSH_PRIVATE_KEY_FILE creates ~/.ssh/config when no user-specific SSH configuration exists and adds a global Host * rule containing StrictHostKeyChecking no. In kas/libcmds.py, ssh_no_host_key_check() runs without checking ctx.managed_env, so the setting persists after kas exits and affects future SSH sessions by the same local user, extending beyond the intended short-lived continuous integration environment. A later SSH connection can therefore accept an attacker-controlled host key without verification, increasing the risk of a man-in-the-middle attack that compromises session confidentiality or integrity. This issue is fixed in version 5.4.
References3
Metrics
- CVSS 3.1
-
3.3
LOW
Score source: CNA
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 1 · as of 9 November 2026
- CWE
- CWE-295
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