CVE-2021-36580: Open Redirect vulnerability exists in IceWarp MailServer IceWarp Server Deep Castle 2 Update 1 (13.0.1.2) via

Q: How do I fix CVE-2021-36580?

icewarp server: upgrade to 13.0.1.2; mail server: upgrade to 13.0.1.2. Exact commands for each OS are on this page.

Q: Is CVE-2021-36580 being exploited?

CVE-2021-36580 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-2021-36580 affect?

CVE-2021-36580 affects icewarp server, mail server. Severity is medium (CVSS 6.1). Open Redirect vulnerability exists in IceWarp MailServer IceWarp Server Deep Castle 2 Update 1 (13.0.1.2) via the referer parameter.

Q: How urgent is CVE-2021-36580?

Priority 40/100. No elevated risk signals yet.

This month

MEDIUM 6.1UPGRADEUPGRADE

CVE-2021-36580 is a medium-severity flaw (CVSS 6.1) affecting icewarp server, mail server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Open Redirect vulnerability exists in IceWarp MailServer IceWarp Server Deep Castle 2 Update 1 (13.0.1.2) via the referer parameter.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.6% (top 24%)
CISA exploited list	No
Weakness	CWE-601
Published	2023-07-27
Last modified	2026-07-09

Publisher (CNA): MITRE · Vendor: icewarp

Last updated 2026-07-09 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-07-27 18:15 UTCPublished CVE record published
2026-07-09 01:16 UTCUpdated Record last modified

icewarp icewarp server UPGRADE

Affected: < 13.0.1.2

Fixed in: 13.0.1.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy icewarp-server || rpm -q icewarp-server || icewarp-server --version

2. UPGRADE to 13.0.1.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade icewarp-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade icewarp-server

Note

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

icewarp mail server UPGRADE

Affected: < 13.0.1.2

Fixed in: 13.0.1.2

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy mail-server || rpm -q mail-server || mail-server --version

2. UPGRADE to 13.0.1.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mail-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mail-server

Note

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

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Nuclei scan template: IceWarp Mail Server - Open Redirect

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-2021-36580?

icewarp server: upgrade to 13.0.1.2; mail server: upgrade to 13.0.1.2. Exact commands for each OS are on this page.

Is CVE-2021-36580 being exploited?

CVE-2021-36580 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-2021-36580 affect?

CVE-2021-36580 affects icewarp server, mail server. Severity is medium (CVSS 6.1). Open Redirect vulnerability exists in IceWarp MailServer IceWarp Server Deep Castle 2 Update 1 (13.0.1.2) via the referer parameter.

How urgent is CVE-2021-36580?

Priority 40/100. No elevated risk signals yet.

Related CVEs

CVE-2020-8512 MEDIUM 6.1 UPGRADE In IceWarp Webmail Server through 11.4.4.1, there is XSS in the /webmail/ color parameter.

References

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