CVE-2021-21390

Public Exploit
MITM modification of request bodies in MinIO

Description

MinIO is an open-source high performance object storage service and it is API compatible with Amazon S3 cloud storage service. In MinIO before version RELEASE.2021-03-17T02-33-02Z, there is a vulnerability which enables MITM modification of request bodies that are meant to have integrity guaranteed by chunk signatures. In a PUT request using aws-chunked encoding, MinIO ordinarily verifies signatures at the end of a chunk. This check can be skipped if the client sends a false chunk size that is much greater than the actual data sent: the server accepts and completes the request without ever reaching the end of the chunk + thereby without ever checking the chunk signature. This is fixed in version RELEASE.2021-03-17T02-33-02Z. As a workaround one can avoid using "aws-chunked" encoding-based chunk signature upload requests instead use TLS. MinIO SDKs automatically disable chunked encoding signature when the server endpoint is configured with TLS.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.26%
Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com
Affected: minio minio
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2021-21390?
CVE-2021-21390 has been scored as a medium severity vulnerability.
How to fix CVE-2021-21390?
To fix CVE-2021-21390, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-21390 being actively exploited in the wild?
It is possible that CVE-2021-21390 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-21390?
CVE-2021-21390 affects minio minio.
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