[luckycharms810]

Well specifically it is sharing the public keys that you have in your SSH folder. It's like trying all your keys in a a keyhole since you don't know which one gets you in. This is really no fault of SSH - the fault lies completely with Github for sharing all their users' public SSH keys.

[saagarjha]

…but they're public keys.

[meddlepal]

This. Exactly what are we afraid of here? It's working as designed.

[ben0x539]

It's not directly a security problem as in your computer is gonna get hacked, but it can ruin your opsec if you don't want people to realize that you're the person controlling a specific key.

[meddlepal]

I would hope if you're doing serious opsec you're using ephemeral keys or isolated virtual environments for various endeavors.

[exabrial]

Yep. I would also hope if you're 'doing opsec' you would know how your tools work.

[luckycharms810]

You are definitely right in that the public keys themselves don’t present a threat. I think on a penetration test this would show up as “Information Revealed” rather than something that is “Exploitable”. By sharing a username - you might be able to correlate this person to other platforms and technically increase your attack surface area.