CVE-2023-2758Network attack vector

Login denial via repeated crafted HTTP headers

Published May 31, 2023 · Updated Jan 9, 2025

Improper interaction-frequency control in CONPROSYS HMI System 3.5.2 and earlier allows remote attackers to deny user logins. The authentication-throttling process inadequately handles repeated requests containing a specific HTTP header element and imposes an extended login block. No authentication or user interaction is required; repeated network requests can prevent legitimate users from signing in, without reported data exposure or modification.

CVSS severity3.7
Low
EPSS probability1.04%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper interaction-frequency control in CONPROSYS HMI System 3.5.2 and earlier allows remote attackers to deny user logins. The authentication-throttling process inadequately handles repeated requests containing a specific HTTP header element and imposes an extended login block. No authentication or user interaction is required; repeated network requests can prevent legitimate users from signing in, without reported data exposure or modification.

The record

CVE
CVE-2023-2758
Published
May 31, 2023
Updated
Jan 9, 2025
Vendor
CONTEC Co., Ltd.
Product
CONPROSYS HMI System (CHS)
Classifications
CWE-799, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 31, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 9, 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=0 <=3.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

CONTEC Co., Ltd. · CONPROSYS HMI System (CHS)version=0 <=3.5.2

Published CVSS scores

3.7Tenable Network Security, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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-799Improper Control of Interaction Frequency
T1499.003Application Exhaustion Flood

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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