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18-Year-Old NGINX Rewrite Module Flaw Enables Unauthenticated RCE

1mon 4d ago by lemmy.world/u/eager_eagle in selfhosted from thehackernews.com

Update your nginx instances

cross-posted from: https://lemmy.world/post/46851448


CVE - Common Vulnerabilities and Exposures system
RCE - Remote Code Execution
PoC - Proof of Concept

Seems to be specific to rewrites using an un-named capture.

grep -rnE "\$[0-9.*].*\?" /etc/ngnix

should show if you have any potentially vulnerable directives in your config.

It's days like this where I'm happy I'm unemployed. I have a group chat with a few friends and they're pushing out patches and it's a bit of a rush.

All my publicly accessible servers update every 6 hours and reboot after whenever they need to. It's rare I need to step in and fix something. I checked a few hours ago and I'm not at risk.

All my publicly accessible servers update every 6 hours and reboot after whenever they need to. It's rare I need to step in and fix something. I checked a few hours ago and I'm not at risk.

not the flex you think it is.

didn't npm have a worm problem a few days ago?

Yep. I wasn't affected thankfully. Didn't realise I was flexing, sorry. Just happy most of my stack is automated and it's quite low maintenance at this point.

Where do I draw the line then? Serious question. If updating every couple hours is bad, then what's safe?

for corporate services we do every 30 days. which is standard. emergency patches get direct support and resolved quickly.

idk, also it is not about the frequency you update, it is usually about how long has it been since package is published to the internet

see concept of min release age https://pnpm.io/blog/releases/10.16

i wonder if other package manager have similar thing or not

You can use pnpm instead of npm. pnpm has a "Delay dependency updates" feature where you can install package versions that are x old only.
See https://pnpm.io/supply-chain-security#delay-dependency-updates

Edit: I just found out, that this can also be specified in npm and yarn: https://gist.github.com/mcollina/b294a6c39ee700d24073c0e5a4e93104

Your friends should do a PoC before they rush to fix random bugs that ostensibly have a high severity.

You should tell that on your group chat. Motruck says you need to slow down and stop jumping at high severity but low exploitabile trash.

Apparently not a massive deal? (I don't know, just linking someone who seems to have a clue)

https://cyberplace.social/@GossiTheDog/116578019563133410

good to know!

For anyone else using SWAG, it looks like a fix is on its way but not available yet. This SWAG issue points to an upstream Alpine package dependency that needs to be updated first. Looking at the source, they just recently committed backported patches, so presumably a new version will be released soon; then the SWAG image can be updated.

I have an old Debian 11 "bullseye" installation running on one of my servers. It's stuck at nginx 1.18.0, but it should theoretically still be covered by Debian 11 LTS security updates, right? https://wiki.debian.org/LTS/Using
nginx/oldoldstable-security,now 1.18.0-6.1+deb11u5

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:

Fewer LettersMore Letters
HTTPHypertext Transfer Protocol, the Web
LTSLong Term Support software version
nginxPopular HTTP server

2 acronyms in this thread; the most compressed thread commented on today has 8 acronyms.

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