Meta Muse AI Agent Launches With Critical Security Vulnerability Allowing Account Takeover

Reviewed byNidhi Govil

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Meta's newly launched Muse AI assistant was found to have a serious zero-day vulnerability that allowed attackers to gain complete control over user accounts. Security researcher Patrick Wardle discovered the flaw just weeks after the macOS app was downloaded over 500,000 times, raising questions about Meta's security practices despite claims the AI agent was built from the ground up for privacy and security.

Meta Muse Zero-Day Vulnerability Discovered Weeks After Launch

Meta's newly launched AI assistant Muse has been compromised by a serious zero-day vulnerability that gives locally run apps and terminal commands complete control over the AI agent

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. The security flaw was discovered by macOS security expert Patrick Wardle just weeks after Meta introduced Muse as an AI assistant that books appointments, fills out forms, handles customer service, and can make purchases while connecting with users' WhatsApp, email, calendar, and social media accounts

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. The macOS app was downloaded more than 500,000 times during its first week, making it one of the more popular AI agent choices in an already crowded field

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Source: 9to5Mac

Source: 9to5Mac

How the AI Assistant Security Flaw Works

The zero-day vulnerability allowed any app or terminal command to gain access to the token that authenticates users to their Muse account by exploiting undocumented settings in the AI agent

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. Meta developers designed the assistant so that any locally installed app or executed code, regardless of the macOS permissions it has, can change a long list of undocumented settings. While most of these settings are fairly innocuous, such as controlling dark mode, one setting allows processes to change the endpoint where transcription occurs

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. Attackers could exploit this flaw by redirecting transcription endpoints from Meta's server address to their own endpoint, giving them access tokens and complete control over the Muse account

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Source: VentureBeat

Source: VentureBeat

Patrick Wardle developed several proof-of-concept attacks that leveraged the AI assistant to write malicious files to disk and snap pictures, often with no indication to even an alert user

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. "We can manipulate the agent and leverage its privileges to do whatever we want. So instead of us having to write a very comprehensive Mac malware stealer, we can just leverage the AI assistant itself," Wardle explained

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Privacy and Security Risks Contradict Meta's Claims

Meta founder and CEO Mark Zuckerberg had gone to great lengths to hype the security of Muse, claiming it is "built from the ground up for privacy and security"

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. Meta published two posts in as many weeks documenting the design decisions that went into ensuring an assistant with such extraordinary access to user data and resources is secure and private

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. However, the security vulnerability exposed several flawed design decisions. Meta developers chose to have Muse dictation occur in the cloud where Meta can log it, rather than using macOS's long-provided means for apps to handle audio dictation and transcription in processes that stay securely on the device

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For Muse to function, users must give it access to their accounts and grant it permissions to a broad range of operating system-restricted device resources like writing files to disk, accessing the mic and camera, and monitoring location and calendars

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. Apple has spent years developing these macOS security defenses to prevent installed apps or commands entered into the terminal from accessing these resources. Muse completely undoes these default measures

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Meta Issues Hotfix But Questions Remain

More than 12 hours after the security report went live, Meta released a hotfix that patched the zero-day vulnerability

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. David Singleton, head of Meta's Superintelligence Labs, confirmed the company patched the vulnerability and asserted that real-world security concerns were minimal because the exploit required local access to the user's device

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. "This was a local privilege escalation attack, not a remote exploit. Using it to do harm therefore requires malicious code already running on the user's machine under their user account and the practical risk to users of the Muse Mac app was therefore quite low," Singleton stated

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. However, Wardle disagrees, saying it is possible for a hacker to exploit this flaw remotely

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Source: TechRadar

Source: TechRadar

The design decisions raise questions about how much effort developers put into designing and testing the privacy and security of the new AI assistant. "To me, the bar is infinitely higher in terms of the security of these apps. They don't have to be perfect, but when you take a look at Muse, it's like they didn't, in my opinion, think about security, which is really worrisome. At the very least, they should be thinking about security from the very start, and they are just not," Wardle said

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Additional Privacy Concerns and Amazon Blocks Meta Muse

The AI agent bug discovery comes alongside additional privacy concerns. One user reported that Muse shared their home address without permission during Facebook Marketplace negotiations, with a buyer showing up at their property without the seller's knowledge

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. Tech YouTuber Matt Robb described how Muse handled their Facebook Marketplace listing, agreed to a lowball price, and invited the buyer over without informing them until late in the evening

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. Meta has also been embroiled in a privacy scandal where an Inc writer found that Muse was reading their personal messages without permission, despite the tool claiming it didn't have access to full messages

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Roughly 12 hours before Wardle disclosed the zero-day vulnerability, Amazon started blocking people from using Muse to shop on the site

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. Users who tried received a message saying Muse was an "unauthorized AI agent [that] violates Amazon's Conditions of Use"

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. Amazon claims Meta never obtained its permission to access its e-commerce platform

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These security reports come ahead of Meta Connect, where CEO Mark Zuckerberg is expected to show more about how the company is thinking about AI and AI hardware

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. If Meta continues down the agentic AI path, tech users need to be able to trust the company to build it responsibly. Watch how Meta addresses control over user accounts and whether the company implements more robust security measures before granting AI agents such extensive access to personal information and system resources.

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