iOS 18.6.1 0-click RCE POC

https://github.com/b1n4r1b01/n-days/blob/main/CVE-2025-43300.md

by akyuu • 11 months ago

228 56 11 months ago

github.com

kirito1337• 11 months ago

Dang that's so cool!

Alifatisk• 11 months ago

I wonder how much this would be worth for Zerodium

gruez3• 11 months ago

$0, given it's patched in ios 18.6.2

crossroadsguy• 11 months ago

Before that obviously. Possibly pc meant to ask if the “finder” would have gone to them instead of dealing with Apple directly.

rafram• 11 months ago

And given that Zerodium has shut down.

tptacek4• 11 months ago

$0, since I don't think Zerodium still exists.

kingforaday• 11 months ago

I know the thread is saying $0 because Zerodium doesn't exist anymore, but there are others. This [0] one for a full chain mobile iOS is at $15M. I agree with tptacek though, the airdrop would reduce the value but you may still be in the low 7 figure range for 0 click RCE.

0. https://advance-sec.com/#bounty

tptacek4• 11 months ago

I don't think this is real. "Full chain Linux desktop" for $10MM? Uh huh.

We recorded a podcast with Mark Dowd a year ago where he said nobody actually gets "list prices" for iOS full chain at $2.5MM (you can make considerably more than that by selling to multiple parties and by selling maintenance) --- and that's iOS, the highest-valued vulnerabilities.

MajesticHobo24• 11 months ago

I AirDropped the PoC to my vulnerable iPhone. It didn't cause a crash until I tried to edit it in the Photos app.

VladVladikoff• 11 months ago

Maybe you need to iMessage it to someone else? Just guessing.

byearthithatius4• 11 months ago

I downloaded the image he provided (https://www.dpreview.com/sample-galleries/4949897610/pentax-...)

The DNG file did have the 01 byte at `2FD00` (from xxd or hexdump -C). However it didn't have a byte position `3E40B`. I tried searching and there is literally no entry at that position. I found a 02 value at 3e40 but not at 3e40b. Is this a typo?

Where did you find it to try and repro?

MajesticHobo24• 11 months ago

You need to click the link that says "RAW (33.0MB)". The filename should be "IMGP0847.DNG".

gruez3• 11 months ago

Note that even though the CVE is for a RCE (remote code execution)[1], this specific PoC is at most a DoS (denial of service). There's more work needed to bypass mitigations for it to be actually usable as a RCE.

[1] https://support.apple.com/en-us/124925

bri3d2• 11 months ago

Where's the 0-click or the RCE here?

I'm actually really curious about how the ITW exploit for this CVE worked; the OOB write is quite obvious in hindsight but going from OOB write to execution on iOS is very much not easy these days, and going from OOB write to sandbox escape should be extremely hard, especially since I thought (?) all image previews in iMessage should be behind BlastDoor. There's a lot of interesting stuff that's still missing here.

gruez3• 11 months ago

Where's the 0-click or the RCE here?

See my other comment. There's an exploit in the wild that uses this bug to get RCE, but this specific example just causes a crash.

bri3d2• 11 months ago

Yes, that's what I'm referring to with

I'm actually really curious about how the ITW exploit for this CVE worked

It's really weird to see only a single OOB write patched for a full 0-click chain in the wild - how did they get code execution? PAC+ASLR bypass? Sandbox escape/kernel escalation?

Literally only RawCamera is patched in the update - were the other bugs in the chain already patched? Too difficult to patch immediately? (ie - close the front door while working on replacing the other locks?)? Still unknown? (ie - found a crash dump from RawCamera but didn't get as sample of the full chain?)

mkhalil• 11 months ago

Seems like it was major enough that it was the lone patch[0] in all active Apple OS's:

macOS Ventura 13.7.8 | macOS Sonoma 14.7.8 | macOS Sequoia 15.6.1

iPadOS 17.7.10 | iPadOS 18.6.2 | iOS 18.6.2

Usually, its multiple CVE's in a security update.

Examples:

- https://support.apple.com/en-us/122375 (macOS Ventura 13.7.5)

- https://support.apple.com/en-us/122718 (macOS Ventura 13.7.6)

- https://support.apple.com/en-us/124151 (macOS Ventura 13.7.7)

--------------------------- References/Sources ---------------------------

[0] https://support.apple.com/en-us/124925 -> https://support.apple.com/en-us/124929 | (124925 -> 124929)

https://support.apple.com/en-us/100100

https://nvd.nist.gov/vuln/detail/CVE-2025-43300#vulnConfigur...

rvz• 11 months ago

Does this affect any of the iOS, iPadOS macOS, tvOS, watchOS 26 Beta?

Reason077• 11 months ago

Apple patched it on August 20, so presumably any release from after this date is not vulnerable.

0x0• 11 months ago

Surprised to see no patch available for watchOS, which can also receive images via iMessage. Not important enough to patch, or not vulnerable, or just not exploited in the wild yet?

transpute4• 11 months ago

For iOS defense, enable Lockdown Mode and reboot daily to evict non-persistent malware, https://www.youtube.com/watch?v=fAhTPMmvrB0

For me, there is only lockdown mode. That is the Apple Experience.

iOS backups can be scanned for the presence of this CVE-2025-43300 DNG processing vulnerability, via OSS tool for iOS forensics, https://github.com/msuiche/elegant-bouncer | https://www.msuiche.com/posts/elegantbouncer-when-you-cant-g...

  ELEGANTBOUNCER is a detection tool for file-based mobile exploits. It employs an innovative approach for advanced file-based threat identification, eliminating the need for in-the-wild samples and outperforming traditional methods based on regular expressions or IOCs. At present, it primarily targets the identification of mobile vulnerabilities such as FORCEDENTRY (CVE-2021-30860), BLASTPASS (CVE-2023-4863, CVE-2023-41064), and TRIANGULATION (CVE-2023-41990) [and recently added CVE-2025-43300].

https://x.com/darknavyorg/status/1959271176062251333

While reproducing the iOS ITW CVE-2025-43300 (support.apple.com/en-us/124925), we accidentally triggered another old DNG image parsing vulnerability. The analysis is still ongoing.

notepad0x902• 11 months ago

I would think mvt and related ioc repos would support these newer indicators,but sadly I'm not seeing that:

https://docs.mvt.re/en/latest/iocs/

transpute4• 11 months ago

It's a different approach:

  Traditional detection approaches like YARA rules, IOC matching, and signature-based systems fall apart when:

   • You don’t have the actual malicious samples to create signatures from
   • The attackers use polymorphic techniques that change file hashes
   • The exploit leverages legitimate file format features in unexpected ways
   • You need to detect future variants of the same technique

  The Philosophy: Structure Over Signatures

  ELEGANTBOUNCER takes a fundamentally different approach to threat detection. Instead of looking for specific byte patterns or known-bad indicators, it analyzes the structural properties of files that make exploits possible.

saagarjha2• 11 months ago

Assuming someone hasn't removed it from the filesystem

ThePowerOfFuet• 11 months ago

For iOS defense, enable Lockdown Mode and reboot daily to evict non-persistent malware

For non-iOS defense, run GrapheneOS with all the default safeguards enabled.

zb3• 11 months ago

Oh, so we'll get another jailbreak soon? Wow, thanks [whatever Israeli agency/company is behind this] :)

makestuff• 11 months ago

How do people even find these types of bugs? Is it just years and years experience allowing you to know where to look?

tomasphan• 11 months ago

Experience /n Fuzzing (when you try a bunch of stuff automatically) /n Reverse engineering the code (using tools like ghidra or hopper)

NoPicklez• 11 months ago

Lots of experience in what are common exploit tactics are and where to look and test if things will break.

Identifying an exploit in iOS requires a significant amount of knowledge in how the OS works, what existing exploits are and how you could chain them together to create a larger exploit.

I've have very limited experience, but reading about how some people identify and exploit these things is extremely impressive.

transpute4• 11 months ago

Fuzzing is one approach.

"Fuzzing ImageIO" (2020), https://googleprojectzero.blogspot.com/2020/04/fuzzing-image...

This blog post discusses an old type of issue, vulnerabilities in image format parsers, in a new(er) context: on interactionless code paths in popular messenger apps. This research was focused on the Apple ecosystem and the image parsing API provided by it: the ImageIO framework. Multiple vulnerabilities in image parsing code were found, reported to Apple or the respective open source image library maintainers, and subsequently fixed. During this research, a lightweight and low-overhead guided fuzzing approach for closed source binaries was implemented and is released alongside this blogpost.

"ImageIO, the infamous iOS Zero Click Attack Vector" (2024), https://r00tkitsmm.github.io/fuzzing/2024/03/29/iOSImageIO.h...

I used LLDB to examine the testHeader functions, it turned out there are three new testHeader functions for different file formats, such as KTX2 and WebP and ETC, so because they were fairly new I thought maybe they have not been fuzzed by Project Zero... I ported Project Zero’s harness to Jackalope fuzzer.. My fuzzing effort found several vulnerabilities [fixed by Apple]..

fmajid• 11 months ago

It's 2025, and Apple clearly still hasn't incorporated fuzzers in their CI and QA. Perhaps I am giving them too much credit in assuming they have any QA in the first place.

tptacek4• 11 months ago

I have no idea what you're talking about; Apple has one of the largest and most sophisticated software security practices on the planet.

pjmlp• 11 months ago

They do, but unfortunately it is built on top of a shacky foundation.

transpute4• 11 months ago

ImageIO has been fuzzed by Google and others, https://news.ycombinator.com/item?id=45034650

user214412412• 11 months ago

is it me or does ios have a myriad of cves in in the image processing/decoder stack? You'd think they'd sandbox in some kind of memory safe framework/lang by now?

muricula• 11 months ago

Look up iMessage's "blastdoor" sandbox: https://support.apple.com/guide/security/blastdoor-for-messa...

kaladin-jasnah• 11 months ago

FORCEDENTRY bypassed this sandbox IIRC. That was a bug in the JBIG2 decoder.

jimmyl02• 11 months ago

unfortunately sandboxes also have bugs which allows for RCE. this is typically called a "full chain" because it chains together a series of bugs (initial decoder exploit + sandbox escape exploit) to gain full RCE

ladyanita22• 11 months ago

For some reason, Apple seems reluctant about using Rust on their operating systems.

steve1977• 11 months ago

That reason is probably called Swift. But they obviously still have many many system libraries written in Objective-C, plain C or C++.

I don't see them using Rust when they have their own language under their full control, especially since both are targeting LLVM anyway.

GoblinSlayer2• 11 months ago

Also image formats are fairly stable, so they are a good candidate for a verified F* parser. Not sure how easy it is for pdf, maybe start with a reasonable subset of it.

mschuster91• 11 months ago

Good luck doing that for stuff like PDF which can include JavaScript in the PDF file itself, or SVG+PDF which both can include raw font files, another reliable source of exploits.

Hilift• 11 months ago

Apple should formalize the iMessage de facto DeviceAndAccountTakeover() API call. I lost count how many zero-click it has. Tim Apple can take the privacy high road all day but it doesn't matter if the code is rotten.

https://citizenlab.ca/2025/06/first-forensic-confirmation-of...

https://citizenlab.ca/2023/09/blastpass-nso-group-iphone-zer...

https://citizenlab.ca/2021/09/forcedentry-nso-group-imessage...

https://citizenlab.ca/2020/12/the-great-ipwn-journalists-hac...

saagarjha2• 11 months ago

This isn't just an iOS thing, and they do sandbox it. Parsers are hard.

aspenmayer• 11 months ago

https://web.archive.org/web/20250827063813/https%3A%2F%2Fs3....

biosboiii• 11 months ago

Also crashes my MacOS Sequoia 15.3.1 Preview App :) https://gist.github.com/AltayAkkus/524acec2b16d4536af0fcee2f...

iOS 18.6.1 0-click RCE POC

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