- The fact that ZIP files include the catalog/directory at the end is such nostalgia fever. Back in the day it meant that if you naïvely downloaded the file, a partial download would be totally useless. Fortunately, in the early 2000s, we got HTTP's Range and a bunch of zip-aware downloaders that would fetch the catalog first so that you could preview a zip you were downloading and even extract part of a file! Good times. Well, not as good as now, but amusing to think of today.
- Debian's `unzip` utility, which is based off of Info-ZIP but with a number of patches, errors out on overlapping files, though not before making a 21 MB file named `0` - presumably the only non-overlapping file.
unzip zbsm.zip
Archive: zbsm.zip
inflating: 0
error: invalid zip file with overlapped components (possible zip bomb)
This seems to have been done in a patch to address https://nvd.nist.gov/vuln/detail/cve-2019-13232https://sources.debian.org/patches/unzip/6.0-29/23-cve-2019-...
- Previously discussed in 2019, https://news.ycombinator.com/item?id=20352439
Someone shared a link to that site in a conversation earlier this year on HN. For a long time now, I've had a gzip bomb sitting on my server that I provide to people that make a certain categories of malicious calls, such as attempts to log in to wordpress, on a site not using wordpress. That post got me thinking about alternative types of bombs, particularly as newer compression standards have become ubiquitous, and supported in browsers and http clients.
I spent some time experimenting with brotli as a compression bomb to serve to malicious actors: https://paulgraydon.co.uk/posts/2025-07-28-compression-bomb/
Unfortunately, as best as I can see, malicious actors are all using clients that only accept gzip, rather than brotli'd contents, and I'm the only one to have ever triggered the bomb when I was doing the initial setup!
- I wonder if there's any reverse zip-bombs? e.g. A realy big .zip file, takes long time to unzip, but get only few bytes of content.
Like bomb the CPU time instead of memory.
- From the bottom of the page
> A final plea
It's time to put an end to Facebook. Working there is not ethically neutral: every day that you go into work, you are doing something wrong. If you have a Facebook account, delete it. If you work at Facebook, quit.
And let us not forget that the National Security Agency must be destroyed.
- In one of my previous jobs, I got laid off in the most condescending way, only to be asked days later by my former boss to send her some documents. If only I knew about this then...
- Okay, so I know back in the day you could choke scanning software (ie email attachment scanners) by throwing a zip bomb into them. I believe the software has gotten smarter these days so it won’t simply crash when that happens - but how is this done; How does one detect a zip bomb?
- Related. Others?
A better zip bomb [WOOT '19 Paper] [pdf] - https://news.ycombinator.com/item?id=20685588 - Aug 2019 (2 comments)
A better zip bomb - https://news.ycombinator.com/item?id=20352439 - July 2019 (131 comments)
by measurablefunc
2 subcomments
- Decompression is equivalent to executing code for a specialized virtual machine. It should be possible to automate this process of finding "small" programs that generate "large" outputs. Could even be an interesting AI benchmark.
- Is it possible to implement something similar but with a protocol that supports compression?
Can we have a zip bomb but with a compressed http response that gets decompressed on the client? There are many protocols that support compression in some way.
by chupasaurus
1 subcomments
- (2019) with last update in 2023.
by KingLancelot
0 subcomment
- [dead]
by gazabbqparty
0 subcomment
- [flagged]