CVE-2021-37588: In Charm 0.43, any two users can collude to achieve the ability to decrypt YCT14 data.

This month

MEDIUM 5.9REMOTEDOWNGRADE

CVE-2021-37588 is a medium-severity flaw (CVSS 5.9) affecting charm. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Charm 0.43, any two users can collude to achieve the ability to decrypt YCT14 data.

Why this priority

Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 40%)
CISA exploited list	No
Weakness	CWE-327
Published	2021-07-30
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: jhu

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

Am I affected?

Timeline

2021-07-30 14:15 UTCPublished CVE record published
2026-06-17 04:00 UTCUpdated Record last modified

jhu charm DOWNGRADE

Affected: 0.43

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.43

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.43 (Debian / Ubuntu)

apt-cache madison charm sudo apt install charm=<VERSION_BEFORE_0.43> sudo apt-mark hold charm

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list charm sudo dnf downgrade charm-<VERSION_BEFORE_0.43> sudo dnf versionlock add charm

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2021-37588?

charm: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-37588 being exploited?

CVE-2021-37588 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-2021-37588 affect?

CVE-2021-37588 affects charm. Severity is medium (CVSS 5.9). In Charm 0.43, any two users can collude to achieve the ability to decrypt YCT14 data.

How urgent is CVE-2021-37588?

Priority 41/100. Remotely exploitable, no login, no user action

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CVE-2022-33734 MEDIUM 6.2 UPGRADE Sensitive information exposure in onCharacteristicChanged in Charm by Samsung prior to version 1.2.3 allows at
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CVE-2022-29180 MEDIUM 5.9 UPGRADE A vulnerability in which attackers could forge HTTP requests to manipulate the `charm` data directory to acces
CVE-2021-37587 MEDIUM 6.5 DOWNGRADE In Charm 0.43, any single user can decrypt DAC-MACS or MA-ABE-YJ14 data.

References

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