Cyber Resilience

CVE-2024-3661

Access Control in Fortinet Forticlient 6.4.0 – 7.2.5

Public PoCAccess Control
Published
06 May 2024
Modified
15 January 2025
Patch / advisory
CVSS Score v3.1 7.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L
EPSS Score 0.041 90th percentile
Risk Priority 63 floored blend · peak EPSS

Summary

CVE-2024-3661 is a high-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Fortinet Forticlient. Its CVSS base score is 7.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 10% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-14 (Permitted Actions Without Identification or Authentication) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

DHCP can add routes to a client’s routing table via the classless static route option (121). VPN-based security solutions that rely on routes to redirect traffic can be forced to leak traffic over the physical interface. An attacker on the…

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same local network can read, disrupt, or possibly modify network traffic that was expected to be protected by the VPN.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-53847Same product class: VPN / SSL gateway
CVE-2025-22252Same product class: VPN / SSL gateway
CVE-2019-5591Same product class: VPN / SSL gateway
CVE-2024-26011Same product class: VPN / SSL gateway
CVE-2024-0012Same product class: VPN / SSL gateway
CVE-2025-0108Same product class: VPN / SSL gateway
CVE-2026-0283Same product class: VPN / SSL gateway
CVE-2024-47574Same product: Fortinet Forticlient
CVE-2025-54660Same product: Fortinet Forticlient
CVE-2018-14634Same product: F5 Big-Ip Access Policy Manager

Affected Assets

fortinet
forticlient
7.4.0 · 6.4.0 — 7.2.5 · 6.4.0 — 7.2.5 · 6.4.0 — 7.2.5
cisco
anyconnect vpn client
all versions
cisco
secure client
all versions
paloaltonetworks
globalprotect
all versions
citrix
secure access client
≤ 24.06.1 · ≤ 24.8.5
f5
big-ip access policy manager
7.2.3 — 7.2.5 · 15.1.0 — 15.1.10 · 16.1.0 — 16.1.5
watchguard
ipsec mobile vpn client
all versions
watchguard
mobile vpn with ssl
all versions
zscaler
client connector
all versions · ≤ 1.5.1.25 · ≤ 4.2.0.282 · 3.7 — 3.7.0.134

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.2.3
  • V6.4.4
  • V10.4.16
  • V12.1.3

Mitigating Controls (NIST 800-53 r5) AI

Directly mandates unique identification and authentication of users before access to functions requiring identity.

Extends the same authentication requirement to non-organizational users accessing critical functionality.

Requires authentication of services before they can invoke or expose critical functions.

Explicitly identifies and limits actions permitted without authentication, preventing critical functions from being exposed.

Information flow enforcement directly stops trusted and untrusted data from being combined by applying rules that govern allowable data movements and combinations.

Associating explicit security attributes with data objects enables enforcement mechanisms that keep trust levels from being mixed inside structures.

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.AA-03 full match
prevents

Directly requires authentication of users/services/hardware, which eliminates missing authentication for critical functions.

PR.PS-06 mostly match
prevents

Secure-development practices (coding standards, reviews, validation) directly prevent mixing trusted and untrusted data inside the same structures.

ID.AM-03 partial match
prevents

Documented data-flow representations make trust boundaries explicit and help surface mixing of trusted/untrusted data.

PR.AA-01 partial match
prevents

Managing identities and credentials is a prerequisite for authentication but does not itself enforce it on critical functions.

PR.AA-05 partial match
prevents

Defining and enforcing authorizations assumes prior authentication and therefore only partially mitigates the absence of authentication.

PR.IR-01 partial match
prevents

Protecting networks from unauthorized access can be undermined by missing authentication but does not address the root authentication gap.

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.

prevents

The control explicitly calls for authentication before any critical function is reached, eliminating the possibility of bypassing authentication for high-value operations.

prevents

Secure architecture principles require explicit trust zones and data segregation, mitigating mixing of trusted/untrusted data.

prevents

Secure coding standards can enforce input validation and data tagging, but do not guarantee architectural separation.

prevents

Mandating authentication requirements for critical functions at the requirements-gathering stage ensures that essential operations are not left unprotected by missing login or verification mechanisms.

mitigates

Mandating authentication for network services and critical functions stops attackers from invoking sensitive operations without credentials, closing gaps where authentication is absent for important capabilities.

prevents

Secure development lifecycle mandates separation of trusted and untrusted data flows, directly preventing mixing in the same structure.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248585 OL 8 must require reauthentication when using the "sudo" command. prevents CWE-306
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-306
RHEL 7 (2 rules)
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-306
  • V-237635 The Red Hat Enterprise Linux operating system must require re-authentication when using the "sudo" command. prevents CWE-306
RHEL 8 (2 rules)
  • V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-306
  • V-237643 RHEL 8 must require re-authentication when using the "sudo" command. prevents CWE-306

References