CVE-2021-27183: An issue was discovered in MDaemon before 20.0.4

Q: How do I fix CVE-2021-27183?

mdaemon: upgrade to 20.0.4. Exact commands for each OS are on this page.

Q: Is CVE-2021-27183 being exploited?

CVE-2021-27183 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-2021-27183 affect?

CVE-2021-27183 affects mdaemon. Severity is high (CVSS 7.2). An issue was discovered in MDaemon before 20.0.4. Administrators can use Remote Administration to exploit an Arbitrary File Write vulnerability. An attacker is able to create new files in any location of the filesystem, or he may be able to

Q: How urgent is CVE-2021-27183?

Priority 52/100. High severity; Public exploit reference

This month

HIGH 7.2UPGRADE

CVE-2021-27183 is a high-severity flaw (CVSS 7.2) affecting mdaemon. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in MDaemon before 20.0.4. Administrators can use Remote Administration to exploit an Arbitrary File Write vulnerability. An attacker is able to create new files in any location of the filesystem, or he may be able to modify existing files. This vulnerability may directly lead to Remote Code Execution.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	7.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	2.7% (top 14%)
CISA exploited list	No
Weakness	CWE-610
Published	2021-04-14
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: altn

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

Am I affected?

Timeline

2021-04-14 23:15 UTCPublished CVE record published
2026-06-17 03:44 UTCUpdated Record last modified

altn mdaemon UPGRADE

Affected: < 20.0.4

Fixed in: 20.0.4

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 20.0.4 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mdaemon

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-2021-27183?

mdaemon: upgrade to 20.0.4. Exact commands for each OS are on this page.

Is CVE-2021-27183 being exploited?

CVE-2021-27183 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-2021-27183 affect?

CVE-2021-27183 affects mdaemon. Severity is high (CVSS 7.2). An issue was discovered in MDaemon before 20.0.4. Administrators can use Remote Administration to exploit an Arbitrary File Write vulnerability. An attacker is able to create new files in any location of the filesystem, or he may be able to

How urgent is CVE-2021-27183?

Priority 52/100. High severity; Public exploit reference

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CVE-2022-29976 MEDIUM 5.4 UPGRADE An Authenticated Reflected Cross-site scripting at BCC Parameter was discovered in MDaemon before 22.0.0 .
CVE-2022-29975 MEDIUM 5.4 UPGRADE An Authenticated Reflected Cross-site scripting at CC Parameter was discovered in MDaemon before 22.0.0 .
CVE-2021-27182 HIGH 8.8 UPGRADE An issue was discovered in MDaemon before 20.0.4
CVE-2021-27181 HIGH 8.8 UPGRADE An issue was discovered in MDaemon before 20.0.4

References

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