alt Hacker NewsUnless the service accepts Lua code from the internet (and that would be a completely insane thing), the CVE-2014-5461 will not apply. And while I have not reviewed every Lua CVE, I bet most (all?) of then require a specifically crafted code, or at least highly-complex user input (such as arbitrary json)
It's important to look at the actual vulnerability at the context, and not just list any CVE which matches by version.
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Its important to maintain your dependencies, by say embedding Lua, rather than rebranding it and then claiming you have no security flaws.
If I can find a CVE that _may_ affect the stack in five minutes, what _actual_ problems lurk there?
You vendor Lua - thus, it _is_ your responsibility to review every Lua CVE. You've set yourself up as the maintainer by vendoring.
> It's important to look at the actual vulnerability at the context, and not just list any CVE which matches by version.
Unfortunately, that's not enough. Even if the vulnerable parts of the code are not being built, heck even if they have been completely erased from the source code, the auditors will still insist that you're vulnerable and must immediately upgrade, or else they will give your software a failing grade.
That seems wildly naive in the post-XSS era. We've been here before, and that kind of analysis turns out to be wrong almost every time.
"Well, sure, this component is insecure but an attacker can't reach it" is like a 50%+ positive signal for an unexpected privilege elevation bug.
I should explain how MaraDNS uses Lua 5.1 (actually, Lunacy, my own fork with security bugs fixed as well as security hardening—including, yes, a patch against CVE-2014-5461), so you can get an idea of its attack surface.
MaraDNS has three components:
• MaraDNS, the authoritative server, which goes back all the way to 2001
• Deadwood, the recursive server, which was started back in 2007
• coLunacyDNS, which allows a DNS server to use Lua scripting; this didn’t exist until the COVID pandemic
Neither MaraDNS nor Deadwood use Lunacy (except as a scripting engine for converting documents); only coLunacyDNS uses Lunacy. coLunacyDNS uses a sandboxed and security hardened version of Lunacy (and, yes, I would accept bugs where someone could escape that sandbox), and the Lua scripts which coLunacyDNS uses can only be controlled by a local user and there is no capability to run Lua scripts remotely.