I was the reporter on this one. If you have Github Actions in your organization, disable them immediately if you're unsure which version of composer your Github Actions run.
Could you elaborate on this bit on why Github's secret masking doesn't work here:
> GitHub Actions' built-in secret masker matches registered values as exact substrings. When the exception message is rendered by Symfony Console it may wrap, embed in In BaseIO.php line N: framing, or interleave with ANSI control sequences. So the masker does not redact, and the plaintext token reaches the log.
What does this log rendering look like such that the token from that code snippet becomes interleaved enough to not be a substring match?
I'm not familiar with composer/Symfony but I would expect something like:
From what I can tell Symfony wraps these errors in a styled error block so it messes with GitHub's masking. For example, newlines breaking up the token are apparently enough to trick the masker since it's not a substring anymore.
For your example:
Line 34: <red>ghs_fdsafdsarewqfdsa...</red>
Is probably long enough in most cases to break to a new line.
Also, those blocks get "interleaved" like this:
<red>ghs_fdsafdsarewqfdsafdsa</red>
<red>fdsardsardsafdsafs......</red>
So there are now </red>'s within the token, also breaking the substring matching.
This is kind of eye-opening for me -- I have never thought about how styled output like this could cause logging leakages.
I don't have an exact count, but during my analysis, I found that ~40 of the top 100 starred repos in the PHP ecosystem were impacted. Primarily by jobs that run `on: schedule` or by a maintainer with an `on: push`
That's my understanding. This seems to only effect PHP projects that use Composer in GitHub actions. Examples being usage of shivammathur/setup-php and or php-actions/composer.
I may be silly but why would you ever want to validate the structure of an opaque authentication key?
Couldn't you just hit an harmless endpoint (e.g. /rate_limit) to see if it returns 401 or not?
GHA have always been a PITA for any serious DevOps; it's quite clear they were designed to integrate in 7 lines of code and then tell everyone who complains that they're doing it wrong.
It is a PITA, but that can be significantly improved IMHO if you just write shell script wrappers for your tasks. Not only does it make it easier to run CI locally, but it also makes it so much easier to move platforms in the future.
When the GH action YAML is just invoking shell scripts, I find it quite pleasant to use
That's mostly been my approach as well... I've also started relying on Deno for a lot of general shell scripting as you can use repository modules without an install step and shebang works outside Windows (or inside with bash).
This is also a good reminder to scan CI logs, not just source code.
Shameless plug: I work on Kingfisher, an Apache 2.0 OSS secret scanner and validator written in Rust, that can also map blast radius and revoke many creds:
It can scan repos, history, and artifacts and validate many findings against provider APIs, as well as revoke many exposed tokens directly from the CLI. Also generates a blast-radius/access-map view so you can see what a leaked credential could reach.
Install:
brew install kingfisher
# or
uv tool install kingfisher-bin
If everyone that can read the logs are people who can read the secrets, then nothing. If there are any log readers who should be be secret readers, its a potentially exposed secret.
