CosmosEscape: Taking over Every Database in Azure Cosmos DB

Posted by uvuv 4 days ago

Comments

Comment by gtowey 4 days ago

> Cosmos DB's engine translated Gremlin queries into .NET code, enforcing a set of restrictions designed to prevent queries from reaching beyond Gremlin operations. These restrictions, however, didn't sufficiently account for .NET reflection

Wow, this is so unbelievably amateurish.

Comment by 4 days ago

Comment by redwood 4 days ago

Incredible that this is the second time Wiz has discovered a global Cosmos DB vulnerability (https://chaosdb.wiz.io/) and a shock that anyone is trusting Microsoft, Azure or in particular Cosmos DB with anything mission critical

Comment by troelsSteegin 4 days ago

"Cosmos Master Key"... I can see why that would have been convenient, but talk about a footgun. Right out of a Marvel movie. Still, if admin backdoor access is business-necessary, is the answer a unique admin access key per account?

Comment by a012 4 days ago

This is not the first time M$ “lost” their master key, it’s their tradition now

Comment by sakisv 4 days ago

Is it me or was there a similar vulnerability reported a few years ago? Something about the attacker getting access to all platform's users' databases, though not sure if it was cosmos or something similar.

Comment by FromOmelas 4 days ago

Yes. you're thinking of https://www.wiz.io/blog/chaosdb-explained-azures-cosmos-db-v...

Comment by ultra2d 4 days ago

This one from a year ago?

https://dirkjanm.io/obtaining-global-admin-in-every-entra-id...

"This vulnerability could have allowed me to compromise every Entra ID tenant in the world (except probably those in national cloud deployments)."

Comment by sakisv 3 days ago

oh ffs, I forgot about this. I was thinking of the other one though from 2021 mentioned in a sibling comment, and it was indeed, again, with cosmos

Comment by chatmasta 4 days ago

There have been a lot. I remember one that was essentially “send the request without an Authorization header.”

Comment by lateral_cloud 4 days ago

It took them 6 months to fix this properly?

Comment by phatskat 4 days ago

Considering that they had to rework things to not use the master key, I can understand the time and effort. From TFA, the DB Gateway handled all Cosmos requests, and used the master key to get an account’s private key and then forward the DB requests. If they had to rearchitect that gateway system, I’m sure it was no small task. Bear in mind, they probably approached this somewhat seriously since Cosmos powers lots of internal M$ tools like Teams and Copilot, not just customer applications.

Comment by delfinom 4 days ago

They patched the vulnerability within 2 days. They spent 6 months rearchitecting their backend. It's a major service for themselves and tens of thousands of customers, you don't vibe code yourself a new database query execution engine overnight.

Comment by dointheatl 3 days ago

Rejecting the premise: who says they fixed it properly?

Comment by jasonvorhe 4 days ago

It's Microsoft, of course. Their org chart basically dictates it.

Comment by uvuv 4 days ago

A critical vulnerability chain in Azure Cosmos DB enabled full read and write access to every Cosmos DB database.

Comment by ryanschaefer 3 days ago

Not showing the actual query is somewhat disappointing