Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessObtain SonicOS administrator credentials
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DeliveryAuthenticate to management interface over network
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ExploitSend crafted overflow payload
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ExecutionTrigger CWE-121 stack-based buffer overflow
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PersistCorrupt stack memory in SonicOS process
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ImpactFirewall crashes, network availability disrupted
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Stack buffer bounds checking
MITRE ATT&CK
1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires valid high-privilege (administrator-level) SonicOS credentials, as confirmed by PR:H in the CVSS 3.1 vector - unauthenticated exploitation is not possible. The attacker must be able to reach the SonicOS management interface over the network (AV:N, AC:L), meaning exposure is blocked if management access is restricted to internal or out-of-band networks and is exploitable only where the management interface is reachable from untrusted segments or the internet. No user interaction beyond authentication is required (UI:N). Impact is strictly limited to availability - a successful exploit crashes the firewall but yields no code execution, data exfiltration, or persistent access. The requirement for prior acquisition of high-privilege credentials is the dominant limiting factor, confining realistic threat scenarios to insider threats, post-compromise abuse, or sessions established via credential theft. |
| Impact | The CVSS 3.1 base score of 4.9 (Medium) is shaped primarily by PR:H, which restricts the exploitable population to actors possessing valid administrator-level SonicOS credentials. The EPSS score of 0.14% at the 34th percentile is low, consistent with CISA SSVC's 'exploitation: none' classification - both signals align in indicating no observed or anticipated widespread exploitation. SSVC also rates the vulnerability as not automatable, meaning it cannot be trivially scripted at scale, which further suppresses realistic threat volume. Technical impact is classified as partial - availability only, with no confidentiality or integrity loss - making this a firewall-disruption scenario rather than a data breach or persistent compromise vector. The primary real-world concern is targeted disruption: an insider threat or an attacker who has already compromised administrator credentials could deliberately take the firewall offline. This makes the vulnerability relevant in post-breach or insider threat models, but low priority relative to pre-authentication or lower-privilege flaws in the same product. |
| Exploit ScenarioDerived | An attacker who has obtained valid SonicOS administrator credentials - through phishing, credential stuffing using leaked passwords, or lateral movement after compromising an internal admin workstation - authenticates to the SonicOS management interface over the network and submits a crafted request that triggers the stack-based buffer overflow. The overflow corrupts the stack, causing the SonicOS process to crash and taking the perimeter firewall offline, potentially disrupting network connectivity for dependent users and systems. No public proof-of-concept code has been identified at the time of analysis. |
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Alert meAnalysisAIv1 – Jul 24, 2026
Stack-based buffer overflow in SonicWall SonicOS enables authenticated remote attackers with high-privilege credentials to crash the firewall, producing a complete denial-of-service condition across multiple SonicOS release trains. Affected deployments span SonicOS 6.5.x, 7.0.x, 7.3.x, and 8.1.x builds per ENISA EUVD-2026-26256 and SonicWall advisory SNWLID-2026-0004. No public exploit code has been identified and CISA SSVC classifies exploitation as none, placing this at lower operational priority despite the network-accessible attack vector.
RemediationAI
Apply the vendor-issued patches documented in SonicWall advisory SNWLID-2026-0004 at https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2026-0004; upgrade to builds above SonicOS 7.0.1-5169, 7.3.1-7013, 8.1.0-8017, or 6.5.5.1-6n depending on your deployed release train. Exact patched version identifiers must be confirmed directly from the SonicWall advisory, as the available data specifies only the last-vulnerable builds. As an immediate compensating control, restrict management-plane access to the firewall to a minimal allowlist of trusted source IP addresses and dedicated management VLANs - this removes the network-reachable attack surface for this class of vulnerability without affecting data-plane traffic. Additionally, enforce multi-factor authentication on all SonicOS administrator accounts and audit for stale or over-privileged accounts to reduce the risk of credential compromise, which is the prerequisite for exploitation.
Affected VersionsENISA
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Technical ContextAI · show details
SonicOS is the proprietary operating system powering SonicWall next-generation firewalls, widely deployed as network perimeter devices in SMB and enterprise environments. CWE-121 (Stack-based Buffer Overflow) identifies the root cause: a memory write operation exceeds the allocated stack buffer, overwriting adjacent stack memory and triggering a process crash. The flaw is reachable over the network by an authenticated user with high-privilege access - consistent with the management-plane exposure typical of SonicOS administrative interfaces. The CPE cpe:2.3:a:sonicwall:sonicos:*:*:*:*:*:*:*:* covers the full SonicOS product line, with EUVD narrowing the affected range to specific builds: 7.0.1-5169 and older, 7.3.1-7013 and older, 8.1.0-8017 and older, and 6.5.5.1-6n and older. The overflow produces only availability impact - no memory disclosure or code execution path has been confirmed.
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Severity by source
AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Admin credentials required (PR:H); management interface network-reachable (AV:N); crash yields total firewall availability loss (A:H) with no confidentiality or integrity impact.
Primary rating from Vendor (sonicwall).
CVSS VectorVendor: sonicwall
Lifecycle Timeline
2DescriptionCVE.org
A post-authentication Stack-based Buffer Overflow vulnerabilities in SonicOS allows a remote attacker to crash a firewall.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
A stack-based buffer overflow occurs when a program writes more data to a buffer located on the stack than it was allocated to hold.
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Wind River VxWorks 6.6 through vx7 has Session Fixation in the TCP component. Rated high severity (CVSS 7.5), this vulne
The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain.
A Host Header Redirection vulnerability in SonicOS potentially allows a remote attacker to redirect firewall management
An improper authentication vulnerability has been identified in SonicWall SonicOS SSL-VPN feature, which in specific con
A Stack-based buffer overflow vulnerability in the SonicOS via HTTP request allows a remote unauthenticated attacker to
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially exe
Wind River VxWorks 6.7 though 6.9 and vx7 has a Buffer Overflow in the TCP component (issue 3 of 4). Rated critical seve
EUVD-2026-26256
NVD
CVE.org
EPSS
Vulnrichment
VulDB
GitHub PoC
Exploit-DB