Menu
The review-first prompt is selected by default. You can switch to a direct command or download a local copy.
Read SKILL.md and any companion files shown by SkillsMP before deciding whether to install.
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
A direct command skips the review prompt. Inspect the source before running it.
npx skills add https://github.com/CyberStrikeus/CyberStrike --skill cis-gcp-cos-5-1-3The command stays on one line. Scroll horizontally to inspect it before copying.
Prefer a local copy? Download the files currently available to SkillsMP.
macOS post-exploitation for credential harvesting, DTrace monitoring, TCC bypass, and stealth operations via native tools
Windows userland post-exploitation for credential harvesting, monitoring, AMSI/ETW bypass, and stealth operations
Kubernetes post-exploitation for container escape, secret extraction, RBAC abuse, and cluster persistence
Based on SOC occupation classification
Showing SKILL.md
| name | cis-gcp-cos-5.1.3 |
| description | Ensure permissions on SSH public host key files are configured |
| category | cis-gcp-cos |
| version | 1.2.0 |
| author | cyberstrike-official |
| tags | ["cis","gcp","container-optimized-os","ssh","sshd","permissions","authentication"] |
| cis_id | 5.1.3 |
| cis_benchmark | CIS Google Container-Optimized OS Benchmark v1.2.0 |
| tech_stack | ["gcp","linux"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
An SSH public key is one of two files used in SSH public key authentication. In this authentication method, a public key is a key that can be used for verifying digital signatures generated using a corresponding private key. Only a public key that corresponds to a private key will be able to authenticate successfully.
If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
Run the following command and verify Access does not grant write or execute permissions to group or other for all returned files:
# find /etc/ssh -xdev -type f -name 'ssh_host_*_key.pub' -exec stat {} \;
File: '/etc/ssh/ssh_host_rsa_key.pub'
Size: 382 Blocks: 8 IO Block: 4096 regular file
Device: ca01h/51713d Inode: 8631758 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2018-10-22 18:24:56.861750616 +0000
Modify: 2018-10-22 18:24:56.861750616 +0000
Change: 2018-10-22 18:24:56.881750616 +0000
Birth: -
File: '/etc/ssh/ssh_host_ecdsa_key.pub'
Size: 162 Blocks: 8 IO Block: 4096 regular file
Device: ca01h/51713d Inode: 8631761 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2018-10-22 18:24:56.897750616 +0000
Modify: 2018-10-22 18:24:56.897750616 +0000
Change: 2018-10-22 18:24:56.917750616 +0000
Birth: -
File: '/etc/ssh/ssh_host_ed25519_key.pub'
Size: 82 Blocks: 8 IO Block: 4096 regular file
Device: ca01h/51713d Inode: 8631763 Links: 1
Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2018-10-22 18:24:56.945750616 +0000
Modify: 2018-10-22 18:24:56.945750616 +0000
Change: 2018-10-22 18:24:56.961750616 +0000
Birth: -
Uid of 0/rootGid of 0/root0644/-rw-r--r-- (no write or execute for group or other)Run the following commands to set permissions and ownership on the SSH host public key files:
# find /etc/ssh -xdev -type f -name 'ssh_host_*_key.pub' -exec chmod 0644 {} \;
# find /etc/ssh -xdev -type f -name 'ssh_host_*_key.pub' -exec chown root:root {} \;
| Controls Version | Control | IG 1 | IG 2 | IG 3 |
|---|---|---|---|---|
| v8 | 3.3 Configure Data Access Control Lists | x | x | x |
| v7 | 5.1 Establish Secure Configurations | x | x | x |