Cyber Resilience

CVE-2024-55591

Auth Bypass in Fortinet Fortiproxy 7.0.0 – 7.0.20

CISA KEVActive ExploitationEUVD ExploitedRansomware-linkedAuth Bypass
Published
14 January 2025
Modified
05 August 2026
KEV Added
14 January 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 0.98 99.9th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2024-55591 is a critical-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Fortinet Fortiproxy. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

The strongest mitigations our analysis identified map to AC-25 (Reference Monitor) and AC-3 (Access 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-2024-55591 is an authentication bypass vulnerability (CWE-288) that affects FortiOS versions 7.0.0 through 7.0.16 and FortiProxy versions 7.0.0 through 7.0.19 as well as 7.2.0 through 7.2.12. The flaw resides in the Node.js websocket module and permits remote attackers to circumvent normal authentication controls through specially crafted requests.

A remote attacker with no prior credentials or user interaction can send crafted websocket requests to obtain super-admin privileges on the affected device, resulting in full control over the system with impacts to confidentiality, integrity, and availability.

Fortinet has published advisory FG-IR-24-535 detailing the issue, and CISA has added the CVE to its Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild.

The EPSS score has reached a peak of 0.9420 with a current value of 0.9412, indicating sustained high exploitation interest following disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS version 7.0.0 through 7.0.16 and FortiProxy version 7.0.0 through 7.0.19 and 7.2.0 through 7.2.12 allows a remote attacker to gain super-admin privileges via crafted requests to Node.js…

more

websocket module.

CWE(s)
KEV Date Added
14 January 2025

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.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1542.002 Component Firmware Stealth
Adversaries may modify component firmware to persist on systems.
T1556 Modify Authentication Process Defense Impairment
Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-24472Same product: Fortinet Fortiosboth on KEV
CVE-2025-22862Same product: Fortinet Fortios
CVE-2018-13379Same product: Fortinet Fortiosboth on KEV
CVE-2018-13383Same product: Fortinet Fortiosboth on KEV
CVE-2024-21762Same product: Fortinet Fortiosboth on KEV
CVE-2018-13382Same product: Fortinet Fortiosboth on KEV
CVE-2024-26009Same product: Fortinet Fortios
CVE-2026-24858Same product: Fortinet Fortiosboth on KEV
CVE-2022-40684Same product: Fortinet Fortiosboth on KEV
CVE-2024-52965Same product: Fortinet Fortios

Affected Assets

fortinet
fortiproxy
7.0.0 — 7.0.20 · 7.2.0 — 7.2.13
fortinet
fortios
7.0.0 — 7.0.17

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 7 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.3
  • V6.6.1
  • V12.1.3

Mitigating Controls (NIST 800-53 r5) AI

Requires a tamperproof, always-invoked reference monitor that structurally blocks bypass via any alternate path.

Enforces authorization checks on every logical access path, eliminating unauthenticated alternate channels.

Mandates unique identification and authentication for all organizational users, covering the primary authentication requirement.

Controls all external and key internal interfaces, reducing the chance of unauthenticated alternate channels.

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

Requiring authentication on every channel and path directly eliminates alternate-path bypasses.

PR.AA-05 mostly match
prevents

Enforcing authorizations and least privilege across all access vectors prevents unauthenticated alternate paths.

PR.IR-01 mostly match
prevents

Protecting networks and environments from unauthorized logical access blocks bypass via undocumented channels.

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.

finds

Security testing can detect alternate-path bypasses but does not prevent them in production.

degrades

Secure authentication control directly mitigates bypass by requiring strong, consistent authentication on all paths.

prevents

Access control policy directly addresses alternate authentication paths by requiring all channels to enforce authentication.

degrades

Authentication information management ensures credentials and mechanisms are consistently applied across all access paths.

prevents

Access rights provisioning and review prevent bypass via unmonitored or alternate channels.

prevents

Privileged access rights control reduces risk of bypass through elevated or alternate paths.

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-248598 There must be no ".shosts" files on the OL 8 operating system. prevents CWE-288
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-288
Oracle Linux 9 (2 rules)
  • V-271757 OL 9 file systems must not contain shosts.equiv files. prevents CWE-288
  • V-271758 OL 9 file systems must not contain .shosts files. prevents CWE-288
RHEL 7 (3 rules)
  • V-204440 Red Hat Enterprise Linux operating systems version 7.2 or newer using Unified Extensible Firmware Interface (UEFI) must require authentication upon booting into single-user and maintenance modes. prevents CWE-288
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-288
  • V-204424 The Red Hat Enterprise Linux operating system must not allow accounts configured with blank or null passwords. prevents CWE-288

References