Yikes.
Yikes.
Probabilistic mitigations work against probabilistic attacks, I guess - but exploit writers aren't random, they are directed, and they find the weaknesses.
"This is true by definition as the QuickJS vulnerability was previously unknown until I found it (or, more correctly: my Opus 4.5 vulnerability discovery agent found it)."
https://github.com/nobodyisnobody/docs/blob/main/code.execut...
Original publication in 2017:
https://m101.github.io/binholic/2017/05/20/notes-on-abusing-...
Lots of vulnerabilites get stopped dead by these mitigations. You almost always need multiple vulnerabilities tied together, which relies on a level of vulnerability density that's tractable. This is not just busywork.
Reports about the ones that are exploitable usually read to me like after finding an entry, the attacker reaches into the well-stocked toolbox of post-entry techniques (return-oriented programming, nop slides, return to libc...) to do the rest of the work.
I hope not, my laptop is slow enough as it is.
WASM adds a layer, but the first thing anyone will do is look for a way to escape it. And unless all software faults and hardware faults magically disappear, it'll still be a constant source of bugs.
Pitching a sandbox against ingenuity will always fail at some point, there is no panacea.
[0] https://instatunnel.substack.com/p/the-wasm-breach-escaping-...
> Leak a libc Pointer via Use-After-Free. The exploit uses the vulnerability to leak a pointer to libc.
I doubt Rust would save you here unless the binary has very limited calls to libc, but would be much harder for a UaF to happen in Rust code.
Combine that with a minimal docker container and you don't even need a shell or anything but the kernel in those images.
AFAICT, static linking just means the set of vulnerabilities you get landed with won't change over time.
I use pure go implementations only, and that implies that there's no statically linked C ABI in my binaries. That's what disabling CGO means.
* It's likely that C implementations will have bugs related to dynamic memory allocation that are absent from the Go implementation, because Go is GCed while C is not. But it would be very surprising if there were no bugs at all in the Go implementation.
What could go wrong with this, right?
/s
The reason I'm so avoidant to using C libraries at all cost is that the ecosystem doesn't prioritize maintenance or other forms of code quality in its distribution. If you have to go to great lengths of having e.g. header only libraries, then what's the point of using C99/C++ at all? Back when conan came out I had hopes for it, but meanwhile I gave up on the ecosystem.
Don't get me wrong, Rust is great for its use cases, too. I just chose the mutex hell as a personal preference over the wrapping hell.
Examples that come to mind: queues that are manipulated inside a loop, slice calls that forget to do length-- of the variable they set in the begin statement, char arrays that are overflowing because the loop doesn't check the length at the correct position in the code, conditions that are re-set inside the loop, like a min/max boundary that is set by an outer loop.
This kind of stuff. I guess you could argue these are memory safety issues. I've seen so crappy loop statements that the devs didn't bother to test it because they still believed they were "smart code", even after sending the devs a PoC that exploited their naive parser assumptions.
In Go I try to write clear, concise and "dumb" code so that a future me can still read it after years of not touching it. That's what I understand under Go's maintainability idiom, I suppose.
While Go isn't perfect and you can certainly write some logic bugs that sufficiently clever use of a more strongly-typed language might let you avoid (though don't underestimate what sufficiently clever use of what Go already has can do for you either when wielded with skill), it has a number of characteristics that keep it somewhat safer than a lot of other languages.
First, it's memory safe in general, which obviously out of the gate helps a lot. You can argue about some super, super fringe cases with unprotected concurrent access to maps, but you're still definitely talking about something on the order of .1% to .01% of the surface area of C.
Next, many of the things that people complain about Go on Hacker News actually contribute to general safety in the code. One of the biggest ones is that it lacks any ability to take an string and simply convert it to a type, which has been the source of catastrophic vulnerabilities in Ruby [1] and Java (Log4Shell), among others. While I use this general technique quite frequently, you have to build your own mechanism for it (not a big deal, we're talking ~50 lines of code or so tops) and that mechanism won't be able to use any class (using general terminology, Go doesn't have "classes" but user-defined types fill in here) that wasn't explicitly registered, which sharply contains the blast radius of any exploit. Plus a lot of the exploits come from excessively clever encoding of the class names; generally when I simply name them and simply do a single lookup in a single map there isn't a lot of exploit wiggle room.
In general though it lacks a lot of the features that get people in trouble that aren't related to memory unsafety. Dynamic languages as a class start out behind the eight-ball on this front because all that dynamicness makes it difficult to tell exactly what some code might do with some input; goodness help you if there's a path to the local equivalent of "eval".
Go isn't entirely unique in this. Rust largely shares the same characteristics, there's some others that may qualify. But some other languages you might expect to don't; for instance, at least until recently Java had a serious problem with being able to get references to arbitrary classes via strings, leading to Log4Shell, even though Java is a static language. (I believe they've fixed that since then but a lot of code still has to have the flag to flip that feature back on because they depend on it in some fundamental libraries quite often.) Go turns out to be a relatively safe security language to write in compared to the landscape of general programming languages in common use. I add "in common use" and highlight it here because I don't think it's anywhere near optimal in the general landscape of languages that exist, nor the landscape of languages that ought to exist and don't yet. For instance in the latter case I'd expect capabilities to be built in to the lowest layer of a language, which would further do great, great damage to the ability to exploit such code. However no such language is in common use at this time. Pragmatically when I need to write something very secure today, Go is surprisingly high on my short list; theoretically I'm quite dissatisfied.
[1]: https://blog.trailofbits.com/2025/08/20/marshal-madness-a-br...
Of course Golang and rust are apples to oranges comparison but still, if someone experienced in golang were to say port to QuickJS to golang and same for rust, aside from some performance cost which can arise from Golang's GC, what would be the security analysis of both?
Also Offtopic but I love how golang has a library for literally everything mostly but its language development ie runtime for interpreted langs/JIT's or transpilation efforts etc. do feel less than rust.
Like For python there's probably a library which can call rust code from Python, I wish if there was something like this for golang and I had found such a project (https://github.com/go-python/gopy) but it still just feels a little less targeted than rust within python which has libraries like polars and other more mature libraries
(The quickjs package in the sibling comment is the original compiled into C. It will probably have all the security quirks of the original as a result.)
But if you are using a VM, you don't even need the Linux kernel: some systems let you compiler your program to run directly on the hypervisor.
See eg https://github.com/hermit-os/hermit-rs or https://mirage.io/
Exactly. "can't translate to safe Rust" is not a good faith argument.
(I’m not trying to be facetious or troll or whatever. Stuff like this is what motivated me to do it.)
Wouldn't GP's approach work with any other executable using libc? Python, Node, Rust, etc?
I fail to see what is specific to either C or QuickJS in the GP's approach.
> Yikes.
Yep.