MS Paint Remote Code Execution Vulnerability

1. Telemetry as implemented is usually sloppy. Even though intuitively one could think that telemetry means “data gets collected locally and fired off to a remote server”, we have seen time and time again that they also build a return path to make the telemetry gathering more powerful. That return path can be a vector.

2. Web browsers have a _huge_ surface and they connect to remote servers constantly. The industry does very well at being proactive and at addressing CVEs but the whole premise makes that very difficult and so we cannot absolutely claim that browsers don’t have RCE(s).

I'd go out on a limb here perhaps, but I'd claim that if your telemetry means that the one SENDING the data gets a RCE by default by it, you're doing telemetry very wrong. Maybe look into different libraries/services than the ones you use today, please.

Then they added automatic HTML parsing of incoming emails, and the attackers cheered.

Turns out paint was the thing almost every customer had installed/had access to, so he worked to the lowest common denominator and got really good at using it. I guess now he'll need to find a new tool to astonish devs with.

And there is the SFI program.

However this is a Windows application, and in spite some Rust advances in WinDev, it is pretty much C and C++ turf, with Rust getting the same warm reception as .NET used to enjoy.

Guess which language is Paint written on?

Nonetheless, they are doubling down on sandboxing Windows, macOS, iOS and Android style, for quite some time, exactly to become security first as you are asking for.

If I still mamaged any windows host, i would be deploying a remove-package script asap to the entire fleet.

Are you using Windows? If so, then yes.

https://msrc.microsoft.com/update-guide/vulnerability/CVE-20...

> How could an attacker exploit this vulnerability?

> An unauthenticated attacker could exploit this vulnerability by sending a specially crafted packet to an affected service over the network. Successful exploitation could allow the attacker to execute code on the target system. No authentication or user interaction is required..

IFF there is a NSA backdoor it likely would be:

- not in paint, but something you can't disable/remove in hardened special purpose windows setups

- not be easily usable by 3rd parties, like some auth accidentally accepting some quite specific other password (e.g. due to some bug reading the expected hash from the wrong place) or similar

lets not forget as much as the NSA might want to spy on you they also want to keep China/Russia out of spying on US companies. A traditional RCE in paint is very counter productive for that.

> An unauthenticated attacker could exploit this vulnerability by sending a specially crafted packet to an affected service over the network. Successful exploitation could allow the attacker to execute code on the target system. No authentication or user interaction is required.

[1] https://msrc.microsoft.com/update-guide/vulnerability/CVE-20...

[0]: https://liquidninja.com/metapad/download.html

Until somebody connects the dots on how the heck MS Paint is accessible over the network, I'm gonna maintain some pretty intense skepticism here.

> https://share.google/aDP2ac9j5AmB13QRo

> LLMs are now unfolding technical debt, poorly written code, and security vulnerabilities accumulated in software that they have created themselves.

> User Interaction: None

> Out-of-bounds read in Windows Paint allows an unauthorized attacker to execute code over a network.

Except for the infamous Dropbox comment.

>The CVSS score of 8.1 marks this as a high‑severity RCE. The EPSS score is not available, and the vulnerability is not listed in CISA’s KEV catalog. Based on the description, the likely attack vector is remote: an attacker can deliver the malicious file over a network connection, for example via Remote Desktop, file shares, or other network‑exposed services that allow users to open images. The lack of EPSS data does not diminish the threat posed by a known RCE, but it does make precise likelihood estimation difficult.

https://app.opencve.io/cve/CVE-2026-83844

> The vulnerable system can be exploited without any interaction from any user.