CVE-2023-40710Network attack vector

Continuous restart loop via unthrottled HTTP requests

Published Aug 24, 2023 · Updated Sep 30, 2024

Denial of service in the Opto 22 SNAP PAC S1 R10.3b built-in web server allows remote attackers to force continuous device restarts. The server accepts a large quantity of HTTP GET requests without adequate resource limits when it is enabled but incompletely configured. The attack requires network reachability and this specific incomplete setup; successful requests repeatedly restart the entire controller and interrupt its control service.

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

Denial of service in the Opto 22 SNAP PAC S1 R10.3b built-in web server allows remote attackers to force continuous device restarts. The server accepts a large quantity of HTTP GET requests without adequate resource limits when it is enabled but incompletely configured. The attack requires network reachability and this specific incomplete setup; successful requests repeatedly restart the entire controller and interrupt its control service.

The record

CVE
CVE-2023-40710
Published
Aug 24, 2023
Updated
Sep 30, 2024
Vendor
Opto 22
Product
SNAP PAC S1
Classifications
CWE-400, CWE-770, T0814
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 30, 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

7.5NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
6.8Dragos, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

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

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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