CVE-2021-36580

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

Published: 2023-07-27 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-36580 is rated Moderate Risk (44.4/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.53%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-36580

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 9.97% 1.53% -8.45%
2 2026-05-16 9.60% 9.97% +0.37%
3 2026-05-15 — 9.60% —

Full EPSS history (54 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-36580

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]

Weakness enumeration for CVE-2021-36580

Affected software / configurations for CVE-2021-36580

Vendor Product Version Raw CPE
icewarp icewarp_server < 13.0.1.2 cpe:2.3:a:icewarp:icewarp_server:*:*:*:*:*:*:*:*
icewarp mail_server < 13.0.1.2 cpe:2.3:a:icewarp:mail_server:*:*:*:*:*:*:*:*

References for CVE-2021-36580

cvelogic Threat Intelligence