CVE-2023-0656Known exploitationPublic exploitNetwork attack vector

Firewall crash via oversized management URI

Published Mar 2, 2023 · Updated Mar 7, 2025

Stack-based buffer overflow in SonicWall SonicOS 7.0.1-5095 and earlier allows remote attackers to crash firewalls through web management. The web-management request handler copies a URI path longer than 1,024 characters into a fixed-size stack buffer; the /stats/ and /Security_Services paths reach the faulty operation. The flaw also affects NSsp 7.0.1-5083 and earlier and NSv 6.5.4.4-44v-21-1551 and earlier; no authentication is required, but web management must be reachable, and SSL VPN is unaffected.

CVSS severity7.5
High
EPSS probability41.32%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in SonicWall SonicOS 7.0.1-5095 and earlier allows remote attackers to crash firewalls through web management. The web-management request handler copies a URI path longer than 1,024 characters into a fixed-size stack buffer; the /stats/ and /Security_Services paths reach the faulty operation. The flaw also affects NSsp 7.0.1-5083 and earlier and NSv 6.5.4.4-44v-21-1551 and earlier; no authentication is required, but web management must be reachable, and SSL VPN is unaffected.

The record

CVE
CVE-2023-0656
Published
Mar 2, 2023
Updated
Mar 7, 2025
Vendor
SonicWall
Product
SonicOS
Classifications
CWE-121, CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 12, 2024Exploitation reportedShadowserver SonicOS honeypot detections
  3. Mar 7, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=SonicOS 7.0.1-5095 and earlier
  2. Affected versionversion=SonicOS NSsp 7.0.1-5083 and earlier
  3. Affected versionversion=SonicOS NSv 6.5.4.4-44v-21-1551 and earlier

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SonicWall · SonicOSversion=SonicOS 7.0.1-5095 and earlier; version=SonicOS NSsp 7.0.1-5083 and earlier; version=SonicOS NSv 6.5.4.4-44v-21-1551 and earlier

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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