Exploited

CVE-2023-28434

MinIO Security Feature Bypass Vulnerability

At a glance

Exploited. Added to CISA’s catalog of exploited vulnerabilities on September 19, 2023.

Affected product: MinIO (category Backup, storage and NAS, indicative classification). Name in CISA’s catalog: MinIO MinIO.

What should I do?

Apply the patches or mitigations from MinIO; if none are available, stop using the product.

Deadline set by CISA for US federal agencies: 21 days (due October 10, 2023). It only binds those agencies, but it is a useful measure of urgency.

The vendor’s specific advisory is listed in the NVD references: CVE-2023-28434 on the NVD website.

Original text of the required action (CISA)

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Timeline

March 22, 2023 Vulnerability published Publication date (NVD)
September 19, 2023 Exploitation confirmed Added to CISA’s KEV catalog
October 10, 2023 CISA deadline Remediation deadline set for US federal agencies

The facts, with their sources

Exploitation confirmed: Yes, on September 19, 2023 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Ransomware: No known use to date That does not guarantee it is not being used: the information is not public. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Hunt for compromise: Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA required action: Apply the patches or mitigations from MinIO; if none are available, stop using the product. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA deadline: October 10, 2023, 21 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Vulnerability published: March 22, 2023 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Product according to CISA: MinIO MinIO Filed by this site under “Backup, storage and NAS” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC

Severity and activity

8.8 / 10 CVSS severity: high

Score from the NVD. Collected Sep 29, 2026.

— Probability of exploitation in the next 30 days (EPSS)

FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.

Description

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`.

MinIO contains a security feature bypass vulnerability that allows an attacker to use crafted requests to bypass metadata bucket name checking and put an object into any bucket while processing `PostPolicyBucket` to conduct privilege escalation. To carry out this attack, the attacker requires credentials with `arn:aws:s3:::*` permission, as well as enabled Console API access.

Summary from CISA (KEV catalog).

CERT-FR advisories

No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.

Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.

Sources for this page

CISA KEV catalog: exploitation, date added, required action, deadline, ransomware.
NVD (NIST): CVSS severity, publication date, description, vendor references.
EPSS (FIRST): probability of exploitation.
CERT-FR: advisories and alerts (in French).
Brand and category: indicative classification by this site (method).