Even "cat readme.txt" is not safe (blog.calif.io)
56 points by arkadiyt 5 hours ago
Drunk_Engineer 22 minutes ago
An almost identical security issue in iterm2 reported 6 years ago:
https://blog.mozilla.org/security/2019/10/09/iterm2-critical...
KerrickStaley 3 hours ago
> At the time of writing, the fix has not yet reached stable releases.
Why was this disclosed before the hole was patched in the stable release?
It's only been 18 days since the bug was reported to upstream, which is much shorter than typical vulnerability disclosure deadlines. The upstream commit (https://github.com/gnachman/iTerm2/commit/a9e745993c2e2cbb30...) has way less information than this blog post, so I think releasing this blog post now materially increases the chance that this will be exploited in the wild.
Update: The author was able to develop an exploit by prompting an LLM with just the upstream commit, but I still think this blog post raises the visibility of the vulnerability.
ezoe 2 hours ago
I guess traditional moratorium period for vulnerability publication is going to be fade away as we rely on AI to find it.
If publicly accessible AI model with very cheap fee can find it, it's very natural to assume the attackers had found it already by the same method.
saddist0 an hour ago
It’s a wrong way to look at things. Just because CIA can know your location (if they want to), would you share live location to everyone on the internet?
LLM is a tool, but people still need to know — what where how.
lxgr 39 minutes ago
chromacity 43 minutes ago
This is cool work, but it's also somewhat unsurprising: this is a recurring problem with fancy, richly-featured terminal apps. I think we had at least ten publicly reported vulns of this type in the past 15 years. We also had vulnerabilities in tools such as less, in text editors such as vim, etc. And notably, many of these are logic bugs - i.e., they are not alleviated by a rewrite to Rust.
I don't know what to do with this. I think there's this problematic tension between the expectation that on one hand, basic OS-level tools should remain simple and predictable; but on the other hand, that of course we want to have pretty colors, animations, and endless customization in the terminal.
And of course, we're now adding AI agents into the mix, so that evil text file might just need to say "disregard previous instructions and...".
SrslyJosh 3 minutes ago
> We'd like to acknowledge OpenAI for partnering with us on this project
Thanks, saved me some reading time.
Bender 4 hours ago
What happens if instead of 'cat readme.txt' one does 'strings -a --unicode=hex readme.txt'? Does iTerm still monkey with it?
alias cat
cat='strings -a --unicode=hex'halJordan 3 hours ago
The whole "cat can hide unprintable characters" is such an old demo. I get this is a novel spin on which unprintable characters were doing but yeah, this was also my thought
Bender 2 hours ago
I'm just used to aliasing cat to strings after working around a lot of red-team penetration testers. They would prank each other and me all the time. Had to also watch out for this one [1].
jdshaffer an hour ago
Is it a problem with "cat" or a terminal problem?
If I wrote my own version of cat in C, simply reading and displaying a single TXT character at a time, wouldn't I see the same behavior?
rezonant an hour ago
As the article shows, it is a bug in iTerm2. cat is just one program that could trigger it, the key thing is outputting attacker controlled text to the terminal when the attacker can control what files are present (ie unzipping a folder that includes a specific executable file at a well chosen location that gets triggered to run when the readme is output to the terminal)
readthenotes1 43 minutes ago
Give this one MS-DOS shell headline would be " why I never am using Microsoft again" or something dramatic like that.
It is a problem in iterm, Apple's overlay, not in the cat program. Program. At least from Reading the article. That's what I got
rezonant 33 minutes ago
It's actually a third party terminal emulator: https://iterm2.com/
CodesInChaos 2 hours ago
I never understood why outputting unescaped data is viewed differently from generating unenclosed html.
Like why doesn't `println` in a modern language like rust auto-escape output to a terminal, and require a special `TerminalStr` to output a raw string.
im3w1l 2 hours ago
I think the problem is that 1) You want to be able to write arbitrary bytes, including shell escape sequences into files. 2) You don't want to accidentally write terminal escape sequences to stdout. 3) Stdout is modeled as a file.
Consider cat. It's short for concatenate. It concatenates the files based to it as arguments and writes them to stdout, that may or may not be redirected to a file. If it didn't pass along terminal escapes, it would fail at its job of accurate concatenation.
Now I don't mean to dismiss your idea, I do think you are on the right track. The question is just how to do this cleanly given the very entrenched assumptions that lead us where we are.
lxgr 43 minutes ago
> that may or may not be redirected to a file
This is usually knowable.
It's a different question whether cat should be doing that, though – it's an extremely low level tool. What's wrong with `less`? (Other than the fact that some Docker images seem to not include it, which is pretty annoying and raises the question as to whether `docker exec` should be filtering escape sequences...)
im3w1l 4 minutes ago
TZubiri 2 hours ago
More like iTerm2 is not safe
ButlerianJihad 2 hours ago
A long, long time ago, it was literally possible to stuff the command buffer of a “dumb terminal” using ESC sequences and spoof keyboard input. So yeah, don’t count on ’cat’ being safe if your terminal isn’t!
tasty_freeze 37 minutes ago
I did this in 1985 on SOROC terminals we had in my first job out of college. However, it depended on the dip switch settings that were under a little door on top of the keyboard.
anthk 13 minutes ago
It is under 9front. There are not terminals, you wan windows with shells on it.
einpoklum an hour ago
Even click-baity titles are not safe.
holoduke 2 hours ago
With LLM tool use potentially every cat action could be a prompt injection