Slack patches potential AI security issue

By Judy Sanhz Published August 22, 2024

Update: Slack has published an update, claiming to have “deployed a patch to address the reported issue,” and that there isn’t currently any evidence that customer data have been accessed without authorization. Here’s the official statement from Slack that was posted on its blog:

Below is the original article that was published.

When ChatGTP was added to Slack, it was meant to make users’ lives easier by summarizing conversations, drafting quick replies, and more. However, according to security firm PromptArmor, trying to complete these tasks and more could breach your private conversations using a method called “prompt injection.”

The security firm warns that by summarizing conversations, it can also access private direct messages and deceive other Slack users into phishing. Slack also lets users request grab data from private and public channels, even if the user has not joined them. What sounds even scarier is that the Slack user does not need to be in the channel for the attack to function.

In theory, the attack starts with a Slack user tricking the Slack AI into disclosing a private API key by making a public Slack channel with a malicious prompt. The newly created prompt tells the AI to swap the word “confetti” with the API key and send it to a particular URL when someone asks for it.

The situation has two parts: Slack updated the AI system to scrape data from file uploads and direct messages. Second is a method named “prompt injection,” which PromptArmor proved can make malicious links that may phish users.

The technique can trick the app into bypassing its normal restrictions by modifying its core instructions. Therefore, PromptArmor goes on to say, “Prompt injection occurs because a [large language model] cannot distinguish between the “system prompt” created by a developer and the rest of the context that is appended to the query. As such, if Slack AI ingests any instruction via a message, if that instruction is malicious, Slack AI has a high likelihood of following that instruction instead of, or in addition to, the user query.”

To add insult to injury, the user’s files also become targets, and the attacker who wants your files doesn’t even have to be in the Slack Workspace to begin with.