CVE-2023-28434
MinIO Security Feature Bypass Vulnerability
MinIO MinIO
Minio is a Multi-Cloud Object Storage framework. Prior to RELEASE.2023-03-20T20-16-18Z, an attacker can use crafted requests to bypass metadata bucket name checking and put an object into any bucket while processing `PostPolicyBucket`. To carry out this attack, the attacker requires credentials with `arn:aws:s3:::*` permission, as well as enabled Console API access. This issue has been patched in RELEASE.2023-03-20T20-16-18Z. As a workaround, enable browser API access and turn off `MINIO_BROWSER=off`.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 19 September 2023. US federal agencies were required to remediate it by 10 October 2023.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 7.9%, which is higher than 94.8% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2023-28434 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2023-28434.
What does CVE-2023-28434 affect?
CVE-2023-28434 affects MinIO MinIO. Minio is a Multi-Cloud Object Storage framework. Prior to RELEASE.2023-03-20T20-16-18Z, an attacker can use crafted requests to bypass metadata bucket name checking and put an object into any bucket while processing `PostPolicyBucket`. To carry out this attack, the attacker requires credentials with `arn:aws:s3:::*` permission, as well as enabled Console API access. This issue has been patched in RELEASE.2023-03-20T20-16-18Z. As a workaround, enable browser API access and turn off `MINIO_BROWSER=off`.
How severe is CVE-2023-28434?
CVE-2023-28434 is rated HIGH with a CVSS base score of 8.8. EPSS puts the probability of exploitation in the next 30 days at 7.9%, higher than 94.8% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 10 October 2023.
How should organisations respond to CVE-2023-28434?
Apply the vendor patch for MinIO MinIO as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.