CVE-2021-39235: In Apache Ozone before 1.2.0, Ozone Datanode doesn't check the access mode parameter of the block token

Q: How do I fix CVE-2021-39235?

ozone: upgrade to 1.2.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-39235 being exploited?

CVE-2021-39235 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-39235 affect?

CVE-2021-39235 affects ozone. Severity is medium (CVSS 6.5). In Apache Ozone before 1.2.0, Ozone Datanode doesn't check the access mode parameter of the block token. Authenticated users with valid READ block token can do any write operation on the same block.

Q: How urgent is CVE-2021-39235?

Priority 47/100. On your watchlist

This month

MEDIUM 6.5WATCHLISTUPGRADE

CVE-2021-39235 is a medium-severity flaw (CVSS 6.5) affecting ozone. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Apache Ozone before 1.2.0, Ozone Datanode doesn't check the access mode parameter of the block token. Authenticated users with valid READ block token can do any write operation on the same block.

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.6% (top 25%)
CISA exploited list	No
Weakness	CWE-732
Published	2021-11-19
Last modified	2026-06-17

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-11-19 10:15 UTCPublished CVE record published
2026-06-17 04:03 UTCUpdated Record last modified

apache ozone UPGRADE

Affected: < 1.2.0

Fixed in: 1.2.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy ozone || rpm -q ozone || ozone --version

2. UPGRADE to 1.2.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade ozone

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ozone

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-39235?

ozone: upgrade to 1.2.0. Exact commands for each OS are on this page.

Is CVE-2021-39235 being exploited?

CVE-2021-39235 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-39235 affect?

CVE-2021-39235 affects ozone. Severity is medium (CVSS 6.5). In Apache Ozone before 1.2.0, Ozone Datanode doesn't check the access mode parameter of the block token. Authenticated users with valid READ block token can do any write operation on the same block.

How urgent is CVE-2021-39235?

Priority 47/100. On your watchlist

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References

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