CVE-2021-3855: Improper Neutralization of Special Elements used in a Command ('Command Injection') vulnerability in Liman Cen

This month

HIGH 8.8UPGRADE

CVE-2021-3855 is a high-severity flaw (CVSS 8.8) affecting port mys. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Improper Neutralization of Special Elements used in a Command ('Command Injection') vulnerability in Liman Central Management System Liman MYS (HTTP/Controllers, CronMail, Jobs modules) allows Command Injection. This issue affects Liman Central Management System: from 1.7.0 before 1.8.3-462.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.8% (top 21%)
CISA exploited list	No
Weakness	CWE-77
Published	2023-03-01
Last modified	2026-06-17

Publisher (CNA): Computer Emergency Response Team of the Republic of Turkey · Vendor: liman

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

Am I affected?

Timeline

2023-03-01 08:15 UTCPublished CVE record published
2026-06-17 04:05 UTCUpdated Record last modified

liman port mys UPGRADE

Affected: >= 1.7.0 and < 1.8.3-462

Fixed in: 1.8.3-462

Safe to downgrade to: a release before 1.7.0

1. Check installed version

apt-cache policy port-mys || rpm -q port-mys || port-mys --version

2. UPGRADE to 1.8.3-462 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade port-mys

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade port-mys

Note

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

3. If no update is available yet, DOWNGRADE to a release before 1.7.0 (Debian / Ubuntu)

apt-cache madison port-mys sudo apt install port-mys=<VERSION_BEFORE_1.7.0> sudo apt-mark hold port-mys

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list port-mys sudo dnf downgrade port-mys-<VERSION_BEFORE_1.7.0> sudo dnf versionlock add port-mys

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-2021-3855?

port mys: upgrade to 1.8.3-462. Exact commands for each OS are on this page.

Is CVE-2021-3855 being exploited?

CVE-2021-3855 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-2021-3855 affect?

CVE-2021-3855 affects port mys. Severity is high (CVSS 8.8). Improper Neutralization of Special Elements used in a Command ('Command Injection') vulnerability in Liman Central Management System Liman MYS (HTTP/Controllers, CronMail, Jobs modules) allows Command Injection. This issue affects Liman Ce

How urgent is CVE-2021-3855?

Priority 50/100. High severity

References

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