You should prepare for the OpenSSL 3.x secvuln

Published on 10/28/2022, 1156 words, 5 minutes to read

Hoooo boy, 2022 keeps delivering. It seems that the latest way things are getting fun is that the OpenSSL project announced a "CRITICAL" patch coming on tuesday for every release of OpenSSL that starts with 3.0. The fixes will be released as OpenSSL 3.0.7. If you run OpenSSL 3.0.0 through 3.0.6, you should consider yourself vulnerable. I will cover how to check later in the post.

For people that only have casually followed the OpenSSL project, note that the last time a "CRITICAL" patch was issued was to mitigate the "Heartbleed" vulnerability. I am going to split my analysis into two parts: facts and speculation.

Facts

The patch to fix this issue will become public on Tuesday, November 1st. At the time of writing, there is currently no publicly visible CVE identifier associated with this issue. I am certain that one will become available on November 1st.

The details on this issue seem to be super embargoed at the moment, but here is what I can tell based on what has been done publicly:

• The Tor project has urged relay owners to upgrade as soon as possible.
• The release for Fedora 37 has been pushed back from October 25th to November 15th.
• Popular tweeter @SwiftOnSecurity tweeted about hearsay about the severity of the issue and that tweet was deleted. No reason for the deletion was given.

I am not a party to the embargo. I don't know how bad this is.

<Cadey>

EDIT(2022 M10 30 16:28): It seems the Go patches coming out on Tuesday are unrelated. I removed a section of the article that mentioned an upcoming Go patch. It is an unrelated security patch apparently.

Speculation

Based on the fact that two projects with TLS support in them are getting security fixes on the same day, I'm thinking this is going to be bad. I am anticipating having to spend the day patching systems and verifying that the vulnerable version of OpenSSL (and the Go programming language) is not in use in both production systems at work and on my personal infrastructure.

Action items you can take

If you are an SRE, system administrator or otherwise going to respond to this issue: now may be a good time to cancel plans for Halloween, or at least abstain from drinking enough alcohol that you will become hung over or using substances that will leave you exhausted the next day.

Finding vulnerable programs

Now may be a good time to identify the systems in your control that use this vulnerable version of OpenSSL. Here is one command you can use to find programs using your distribution's package of OpenSSL:

sudo lsof -n | grep libssl.so.3

For example, here's what such a row could look like (extraneous details snipped):

From this you can tell that the code that powers my website loads openssl for some reason, and that package will need to be updated.

On Ubuntu you can search for what packages own which files using dpkg -S like this:

xe@nneka-sakuya:~$ sudo dpkg -S /usr/lib/x86_64-linux-gnu/libssl.so.3
libssl3:amd64: /usr/lib/x86_64-linux-gnu/libssl.so.3

You can get the version information of the package libssl3 using apt-cache show like this:

apt-cache show libssl3

This will show information like this.

Recording things

This is something you can do ahead of time and will help you triage this issue before you apply fixes in production.

• Create a list of machines that you have administrative access to and run that command on each of them.
• Identify the version of OpenSSL that each program is using (or the version of OpenSSL the system is running) and use systemctl status to trace things back to the corresponding services. Depending on facts and circumstances, this update may have effects on those services.
• Use this to create a list of potential "blast damage", or ways that services could fall over and cause issues. Communicate this information to support teams.

By now, you should have a list of all of the machines with vulnerable versions of OpenSSL and all of the services that will need to be restarted.

<Cadey>

Of course, if something statically links OpenSSL for some reason, all bets are off. You may have to check the build recipes of every bit of custom software you ship on your systems. Distribution packages are usually good about using the system level dynamically linked binaries, but most language-level package manager ecosystems grew around distribution level packages so depending on the ecosystem in question you may have to do a lot of digging.

Plan for patch tuesday actions

When the patches drop on Tuesday, you should do one of the two things:

• Update machines as quickly as possible.
• Isolate machines from the Internet entirely until you can update the OpenSSL package on that system.

At this time it is not known if this is a client or server vulnerability. If it is a server vulnerability (one that affects services with OpenSSL being used to encrypt data in-transit), then it is probably best to turn off public-facing daemons, upgrade your packages, and then turn them back on. If this is a client vulnerability triggered by malicious servers then a lot of things will change about the response process. You may have to copy the target packages over SSH, install them manually, and then bring your external facing services back up. Depending on how much you trust your network, it may be safe to just install from your distributions package servers.

When your distribution tells you the version of the packages that have the vulnerability fixed, record that as your target version of OpenSSL. Ensure every system, docker image and virtual machine has OpenSSL updated. This may take a while. You may want to split the work between teammates.

I am really hoping that this doesn't end up sucking, but I would probably plan for it being about as bad as Heartbleed. Above all though, take care of yourself and try not to stress out about this too much. Everyone on the Internet is going to be as vulnerable as you are right now.

Facts and circumstances may have changed since publication. Please contact me before jumping to conclusions if something seems wrong or unclear.

Tags: openssl, vuln, noxp