Cyber Resilience

CVE-2025-40630

Open Redirect in Icewarp Mail Server 11.4.0

Open Redirect
Published
16 May 2025
Modified
17 June 2026
CVSS Score v4 5.1
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0045 37th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-40630 is a medium-severity Open Redirect (CWE-601) vulnerability in Icewarp Mail Server. Its CVSS base score is 5.1 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Phishing (T1566); ranked at the 37th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

Open redirection vulnerability in IceWarp Mail Server affecting version 11.4.0. This vulnerability allows an attacker to redirect a user to any domain by sending a malicious URL to the victim, for example “ https://icewarp.domain.com//<MALICIOUS_DOMAIN>/%2e%2e” https://icewarp.domain.com///%2e%2e” . This vulnerability has been…

more

tested in Firefox.

CWE(s)
CWE-601

Related Threats

MITRE ATT&CK Enterprise Techniques

T1566 Phishing Initial Access
Adversaries may send phishing messages to gain access to victim systems.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-40779Same vendor: Icewarp
CVE-2025-40632Same product: Icewarp Mail Server
CVE-2025-40631Same product: Icewarp Mail Server
CVE-2023-39699Same product: Icewarp Mail Server
CVE-2023-39700Same product: Icewarp Mail Server
CVE-2026-24768Shared CWE-601
CVE-2025-34504Shared CWE-601
CVE-2023-46750Shared CWE-601
CVE-2024-24764Shared CWE-601
CVE-2025-8066Shared CWE-601

Affected Assets

icewarp
mail server
11.4.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V3.7.2

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match

Input validation directly checks and rejects untrusted redirect targets before they are used in a response.

AC-4 Information Flow Enforcement partial match

Information flow enforcement can restrict redirects to only approved/trusted destinations, stopping untrusted user-supplied URLs from being followed.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and untrusted-redirect controls that prevent CWE-601.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.23 Web filtering partial match
mitigates

Preventing access to attacker-controlled or malicious sites stops users from being redirected to untrusted locations via open-redirect or phishing links.

References