CVE-2023-40709Network attack vector

Device crash via unthrottled ICMP request flood

Published Aug 24, 2023 · Updated Sep 13, 2024

Resource exhaustion in Opto 22 SNAP PAC S1 firmware R10.3b allows remote attackers to crash the controller with excessive ICMP requests. The built-in web-server configuration fails to limit resources consumed when the controller receives a large ICMP request volume. The flaw is reachable without authentication only when the built-in web server is enabled but not completely set up and configured.

CVSS severity6.8
Medium
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Opto 22 SNAP PAC S1 firmware R10.3b allows remote attackers to crash the controller with excessive ICMP requests. The built-in web-server configuration fails to limit resources consumed when the controller receives a large ICMP request volume. The flaw is reachable without authentication only when the built-in web server is enabled but not completely set up and configured.

The record

CVE
CVE-2023-40709
Published
Aug 24, 2023
Updated
Sep 13, 2024
Vendor
Opto 22
Product
SNAP PAC S1
Classifications
CWE-770, CWE-400, T0814
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 13, 2024Record 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=R10.3b

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Opto 22 · SNAP PAC S1version=R10.3b

Published CVSS scores

6.8Dragos, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
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 exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
CWE-400Uncontrolled Resource Consumption
T0814Denial of Service

Public exploit references

No public exploit references are available in this record.

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

Technologies

Your stack

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Your stack

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