3 ms·

>But it runs that decoder inside the attacker-controlled directory (unzipped archive) >There a malicious struct.py shadows Python’s standard implementation I

• stellamariesays 2mo ago
  [flagged]
• DanielHB 2mo ago
  Claude ran npm update (update all dependencies to the latest version compatible with the semver specified) in my repo without telling me when trying to fix some problems. Given that only updates the dependency lock-file I didn't notice and it caused several hours of debugging for me. It is quite sneaky how LLM output can sometimes bypass human verification like that. No one is going around checking every single line change in auto-generated files. Someone could easily sneak a malicious dependency in there through some online tutorial that the LLM searches for.
  • kouteiheika 2mo ago
    > No one is going around checking every single line change in auto-generated files. There's a simple fix for your particular case: commit your lock fine (which you should do) and always review the diff (which you should also do). (:
    • Forgeties79 2mo ago
      “But I have an agent for that.”
    • catlifeonmars 2mo ago
      Heh, I also notice some coding agents like to explicitly git ignore the lockfile.
    • eterm 2mo ago
      You've made me realise a good signal for bug hunting: Search repos with lock files listed in their .gitignore. It's the sort of terrible practice that someone might be frustrated into taking after a nasty merge conflict, and signals a willingness to cut corners.
      • DanielHB 2mo ago
        My lockfile was not gitignored, I had made significant changes to package.json so I was expecting diffs in the lockfile. I just don't usually read lockfile diffs and claude inadvertently updated a few dozen packages to new minor versions without me noticing. In fact I only realized the problem after I looked at the lockfile diff.
        • jrockway 2mo ago
          Makes sense. This is why I like using jj, because "update deps" and "fix bug" are going to be two separate commits, and when "fix bug" has changes in the lock file, the red flags go up. Claude seems to be super good at jj so that can take the edge off as well.
          • lesam 2mo ago
            Why do you need jj for this? I'd usually make incremental commits with git, and I'm wondering how jj levels it up.
      • esperent 2mo ago
        > You've made me realise a good signal for bug hunting: Search repos with lock files listed in their .gitignore. What would be the point of that? Do you just go around hunting for bugs in random repos?
        • eterm 2mo ago
          Sure, in the spirit of open source, why not? It's a hobby, and it scratches an itch. I very much enjoy deconstructing things more than putting them together. We also live in a world where a package written by someone learning to code ended up critically underpinning the entire ecosystem and is downloaded 500 million times a month. Ignoring the eco-terror aspect of that for now, it means there's an awful lot of code out there which is finding itself under constant attack by a fleet of hostile AI. I don't personally believe that the solution to that is "more AI", which firstly just overwhelms maintainers and secondly surrenders our human agency to a giant machine, with a hope that the "good" side can out-spend the bad. Nor do I think the solution is to abandon the open internet and retreat behind corporate walls into curated spaces, "benevolently" protected by giant companies. Which means holding on to the open internet requires a human approach, and any signal to help amplify the work there is a benefit.
    • DanielHB 2mo ago
      I made changes to my dependency lists in the same code where Claude ran npm update. The lockfile diff was a few hundred lines after I undid what Claude did. And yes, eventually I did check the lockfile changes and spotted the problem. I just usually don't check the lockfile that throughly.
      • kouteiheika 2mo ago
        > I made changes to my dependency lists in the same code where Claude ran npm update. ...but was it in the same commit? Two "update lockfile" commits, one yours and one Claude's should have made this obvious, no? Here's another useful rule of thumb: never mix your changes with the agent's changes. Agent always starts with a clean repository (no pending, uncommited human changes). You always start with with a clean repository (no pending, uncommited agent changes). Personally I have this in my `AGENTS.md`: ## Commit early, commit often You are allowed and encouraged to produce small, self-contained commits. Never `git push`; I will always review and rebase the full history and do the push myself. Commit messages should be *short* and on-point. They're there for *me* to review your work, and *not* a public historical artifact. So my workflow is usually this: start agent with a clean repository, tell it to do a thing, it works in the background, then once it's finished I come back, review, rewrite and clean up half of what it wrote, then maybe iterate some more with it, and finally do an interactive git rebase to get a clean commit history.
        • DanielHB 2mo ago
          I don't let claude make commits for me, every commit is my own. I check the diffs before commiting. > never mix your changes with the agent's changes yeah, but if you don't want to lose your existing context sometimes you have to. When I do, I tell claude to check the diff on the files I changed, which is quite annoying to be honest. But still easier than telling claude to do _very specific line-change_ on file X.
          • kouteiheika 2mo ago
            > yeah, but if you don't want to lose your existing context sometimes you have to Sorry, I'm not sure I follow. What do you mean by "lose your existing context"? Can't you just... commit in turns? It's not like you're editing files while your agent's also editing in parallel, right? Again, the trick is to treat the commits as throwaway checkpoints/packets of work. They don't need to be pretty, nor need to make sense. The point where you clean that mess up is when you're done and you're doing an interactive rebase at the end. At least that's how I work.
    • nomel 2mo ago
      That's a manual step, not a solution. the solution is just boring basic file permissions. Treat Claude as semi hostile user. If you don't want them accessing your files, set the permissions to exclude them (like require sudo). I already do this for my unit tests, because Claude will "fix" the tests so they'll pass.
  • fg137 2mo ago
    I cannot tell you how much time I have saved by stopping Claude and asking, "what are you doing?" At least 50% of the time, Claude "realizes" it already has all the information but is doing something that's unnecessary for the current work, stop, and tell me the previous step has completed. People complain about approval prompts etc and have Claude run in fully autonomous mode. Outside small bug fixes, I just never find that useful. It helps me immensely to see what commands Claude is running to understand where the work is going.
    • UpsideDownRide 2mo ago
      Also Claude often cooks up atrocious overengineered ideas but responds pretty well to being guided hands on to the desirable scope.
  • tuwtuwtuwtuw 2mo ago
    Maybe I don't understand you correctly but if your lock file isn't in Git then you have bigger security issues than LLM output, given the last years NPM worms. Unless you're a single developer and the file on disk is the primary source of truth.
  • sippeangelo 2mo ago
    Worse: Claude installed packages by just typing versions into package.json instead of running `pnpm install x`, then when running `pnpm install`, discovering that the package versions are too new and incompatible due to the default `minimumReleaseAge`, then proceeding to circumvent this by disabling `minimumReleaseAge` and running a full package update :)
  • YavenTeam 2mo ago
    [dead]
  • smashed 2mo ago
    When testing Claude code in auto mode in a fresh sandbox with a docusaurus website freshly cloned, I asked: Can you see the docs folder with the git project? It was in auto mode. So it immediately saw a docusaurus site (good) but instead of stopping there, it installed nodejs from a static binary download (no root access so only way), ran npm install, started the dev server and confirmed the project worked. That is some crazy amount of leeway for an intent based classifier. I'm not surprised it's full of holes, and it seems to be 100% by-design.
• ricardobeat 2mo ago
  It is kind of crazy that Python allows shadowing standard library modules so easily. If this was a 'feature' in node.js it would have been front-paged and bashed to death in the blink of an eye.
• js2 2mo ago
  > That definitely doesn't seem to me like how that should be designed, magically silently importing everything you see and overriding basic functionality. Modern Python supports various options, notably `-I` (isolated) and `-P` (`PYTHONSAFEPATH`, implied by `-I`) to help with this. But neither prevent shadowing. For a robust solution, you should typically structure your code into packages and use absolute imports. Here's a decent primer on the topic: https://www.py4u.org/blog/python-problem-with-local-modules-shadowing-global-modules/ https://www.py4u.org/blog/python-problem-with-local-modules-... edit: `-I` is mentioned in TFA.
• rappatic 2mo ago
  I have taught Python to high schoolers before and this is frustratingly common. Students will name their files `string.py` or similar and get crashes with esoteric error messages. It's a difficult stumbling block for someone who's just learning the basics