Security Resilience

CVE-2023-47539

Fortinet Fortimail 7.4.0

Published
18 March 2025
Modified
24 July 2025
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.011 64th percentile
Risk Priority 73 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-47539 is a critical-severity Improper Access Control (CWE-284) vulnerability in Fortinet Fortimail. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 36% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-47539 is an improper access control vulnerability (CWE-284) in FortiMail version 7.4.0 when configured with RADIUS authentication and the remote_wildcard option enabled. This issue allows a remote unauthenticated attacker to bypass administrative login via a crafted HTTP request. The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity due to its network accessibility, low complexity, and potential for high impacts across confidentiality, integrity, and availability.

A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted HTTP request to the targeted FortiMail instance under the specified configuration. Successful exploitation grants unauthorized administrative access, enabling the attacker to perform privileged actions on the device.

Mitigation details are available in the FortiGuard PSIRT advisory at https://fortiguard.com/psirt/FG-IR-23-439.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

An improper access control vulnerability in FortiMail version 7.4.0 configured with RADIUS authentication and remote_wildcard enabled may allow a remote unauthenticated attacker to bypass admin login via a crafted HTTP request.

CWE(s)

Related Threats

CVEs Like This One

CVE-2023-36635Same vendor: Fortinet
CVE-2026-35616Same vendor: Fortinet
CVE-2023-33301Same vendor: Fortinet
CVE-2023-47536Same vendor: Fortinet
CVE-2024-36505Same vendor: Fortinet
CVE-2023-25605Same vendor: Fortinet
CVE-2023-41679Same vendor: Fortinet
CVE-2023-36638Same vendor: Fortinet
CVE-2025-59810Same vendor: Fortinet
CVE-2024-45326Same vendor: Fortinet

Affected Assets

fortinet
fortimail
7.4.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Directly enforces approved authorizations for logical access, stopping unauthorized actors from reaching resources.

Enforces flow-control policies that restrict information movement between subjects and objects.

Documents duties and assigns access so that no single account can bypass intended restrictions.

Limits each account to the minimum privileges needed, reducing the chance of unauthorized access.

Defines account types, assigns/removes access, and reviews accounts to ensure only authorized actors can reach resources.

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.

blocks

A.5.1 only requires that an information security policy and topic-specific policies (including on access control) exist and are reviewed; it does not itself enforce, implement or act on any access restriction, so the weakness can still be exploited (per the owner's explicit rule that governance/dependency clauses score none on effect verbs).

blocks

A.5.15 directly mandates determining requirements, defining/implementing topic-specific access control policy+rules (with explicit references to 8.3, 5.16, 5.18), and enforcing authorized access while preventing unauthorized access, which squarely stops exploitation of most CWE-284 instances; the bounded remainder is the physical slice (explicitly delegated to 7.2-7.4) plus any second-order defects like path traversal that are not authorization decisions.

blocks

A.5.16's identity lifecycle (unique binding, timely disable/remove, no duplicates, oversight of shared/non-human) directly stops most improper access by ensuring the actor in an access decision is correctly identified and authorized; the bounded remainder is non-identity mechanisms in CWE-284 such as path traversal or CSRF that do not turn on actor identity at all.

blocks

A.5.18 directly governs the provisioning, review, adjustment and timely revocation of both physical and logical access rights per business rules, segregation of duties and risk-evaluated changes/terminations; this stops most unauthorized-actor exploitation paths named by CWE-284, with a bounded remainder (e.g. path-traversal or CSRF cases that are not authorization decisions at all)

blocks

A.5.2 defines and assigns roles/responsibilities for protection of information and risk acceptance; it does not itself enforce any access decision and cannot stop exploitation of improper access control (per the owner's labeling rule: governance/dependency clauses do not score on prevent/mitigate verbs)

finds

Ongoing audits and performance reviews of suppliers detect and correct situations where access controls or privilege assignments are weaker than contractually required, limiting an attacker's ability to exploit improper access control in the supplier's environment.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-284, a pillar-level weakness. Rules are authored against its narrower children: CWE-749, CWE-1220.

References