Cyber Resilience

CVE-2024-40766

Sonicwall Sonicos ≤ 5.9.2.14-13o

CISA KEVActive ExploitationEUVD ExploitedRansomware-linked
Published
23 August 2024
Modified
31 October 2025
KEV Added
09 September 2024
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 0.18 97th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2024-40766 is a critical-severity Improper Access Control (CWE-284) vulnerability in Sonicwall Sonicos. 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 3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities 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.

An improper access control vulnerability exists in the SonicWall SonicOS management interface that can permit unauthorized resource access and, under certain conditions, trigger a firewall crash. The flaw affects SonicWall Firewall devices running Gen 5 and Gen 6 firmware as well as Gen 7 devices on SonicOS 7.0.1-5035 and earlier releases. The issue carries a CVSS 3.1 base score of 9.8, reflecting network-accessible exploitation without authentication or user interaction.

An unauthenticated remote attacker can send specially crafted requests to the management access component to bypass access controls, potentially obtaining sensitive configuration data or disrupting device availability. Because the vector requires no credentials, the exposure extends to any internet-facing SonicWall appliance whose management services are reachable.

The vendor advisory SNWLID-2024-0015 and the CISA Known Exploited Vulnerabilities catalog both list the issue, confirming that public exploitation has been observed. Administrators are advised to apply the patches or configuration mitigations published by SonicWall for the affected firmware branches.

EPSS for the CVE rose from a low baseline to a peak of 0.0908 on 2025-12-11 before receding to the current value of 0.0344, indicating that exploitation interest increased after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

An improper access control vulnerability has been identified in the SonicWall SonicOS management access, potentially leading to unauthorized resource access and in specific conditions, causing the firewall to crash. This issue affects SonicWall Firewall Gen 5 and Gen 6 devices,…

more

as well as Gen 7 devices running SonicOS 7.0.1-5035 and older versions.

CWE(s)
KEV Date Added
09 September 2024

Related Threats

Threat-Actor AttributionAI

Akira (G1024)
Akira ransomware exploited this SonicWall SSLVPN flaw (CISA KEV ransomware-use noted; vendor and CISA reporting).

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.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1021 Remote Services Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.001 Remote Desktop Protocol Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.002 SMB/Windows Admin Shares Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.003 Distributed Component Object Model Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2021-22941Shared CWE-284both on KEV
CVE-2019-11634Shared CWE-284both on KEV
CVE-2020-2506Shared CWE-284both on KEV
CVE-2019-1653Shared CWE-284both on KEV
CVE-2026-34908Shared CWE-284both on KEV
CVE-2023-38205Shared CWE-284both on KEV
CVE-2014-3120Shared CWE-284both on KEV
CVE-2012-5076Shared CWE-284both on KEV
CVE-2024-20767Shared CWE-284both on KEV
CVE-2016-3427Shared CWE-284both on KEV

Affected Assets

sonicwall
sonicos
≤ 5.9.2.14-13o · ≤ 6.5.2.8-2n · ≤ 6.5.4.15.116n

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 8 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V10.3.5

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 (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-05 mostly match
prevents

PR.AA-05 directly enforces policy-based access management and least privilege, eliminating most improper-access-control defects, yet CWE-284 also covers implementation flaws and design gaps outside a single management control.

PR.PS-01 mostly match
prevents

Hardened baselines and deviation monitoring directly eliminate most configuration-induced access-control defects, yet CWE-284 also encompasses code-level and design flaws outside the scope of configuration management alone.

PR.PS-06 mostly match
prevents

Secure SDLC practices catch most access-control defects during design/coding/testing (mostly), yet leave residual risk from runtime configuration, architecture, and operational controls (partial).

PR.AA-01 partial match
prevents

PR.AA-01 supplies managed identities/credentials that support but do not implement access-control decisions, so it only partially prevents CWE-284 in either direction.

PR.AA-03 partial match
prevents

Authentication directly blocks unauthenticated actors (partial prevention of CWE-284) but leaves authorization logic, policy enforcement, and role checks untouched, so the control neither eliminates nor fully mitigates the broader weakness.

PR.DS-01 partial match
prevents

PR.DS-01 encryption mitigates impact of failed access checks on stored data but neither implements nor constrains access-control logic itself.

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

Defining and enforcing explicit access rights and restrictions for each entity directly stops the assignment of permissions that exceed what is required, eliminating the root condition that allows improper access control.

prevents

Formal authorization, role-based provisioning, and timely revocation of access rights directly stop the creation of accounts or permissions that exceed what the business actually needs.

prevents

By enforcing explicit rules on which identities or groups may perform read, write, delete or execute operations and by denying anonymous access to sensitive data, the control directly stops the creation of overly permissive or missing access-control checks.

prevents

Requiring one-to-one mapping of identities to entities and timely removal of unused identities directly stops attackers from leveraging stale or shared accounts to bypass access restrictions.

prevents

By explicitly transferring security roles and responsibilities when personnel change jobs or leave, the control reduces the chance that former employees retain access rights they no longer need, thereby limiting improper access control.

prevents

Physical entry controls enforce explicit authorization and authentication at every access point, directly stopping unauthorized actors from reaching information-processing assets.

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-248597 There must be no "shosts.equiv" files on the OL 8 operating system. prevents CWE-284
  • V-248598 There must be no ".shosts" files on the OL 8 operating system. prevents CWE-284
Oracle Linux 9 (2 rules)
  • V-271758 OL 9 file systems must not contain .shosts files. prevents CWE-284
  • V-271757 OL 9 file systems must not contain shosts.equiv files. prevents CWE-284
RHEL 7 (2 rules)
  • V-204606 The Red Hat Enterprise Linux operating system must not contain .shosts files. prevents CWE-284
  • V-204607 The Red Hat Enterprise Linux operating system must not contain shosts.equiv files. prevents CWE-284
RHEL 8 (2 rules)
  • V-230283 There must be no shosts.equiv files on the RHEL 8 operating system. prevents CWE-284
  • V-230284 There must be no .shosts files on the RHEL 8 operating system. prevents CWE-284

References