CVE-2023-34998Public exploitNetwork attack vector

Authentication bypass via replayable cleartext credential structure

Published Sep 5, 2023 · Updated Feb 13, 2025

Authentication bypass in Open Automation Software OAS Platform 18.00.0072 allows man-in-the-middle attackers to issue privileged requests. The OAS Engine sends its U_EP authentication structure in cleartext and accepts a captured structure in later attacker-crafted requests. Access to legitimate administrator traffic is required; replay grants that account's OAS privileges until the account is deleted.

CVSS severity8.1
High
EPSS probability1.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Open Automation Software OAS Platform 18.00.0072 allows man-in-the-middle attackers to issue privileged requests. The OAS Engine sends its U_EP authentication structure in cleartext and accepts a captured structure in later attacker-crafted requests. Access to legitimate administrator traffic is required; replay grants that account's OAS privileges until the account is deleted.

The record

CVE
CVE-2023-34998
Published
Sep 5, 2023
Updated
Feb 13, 2025
Vendor
Open Automation Software
Product
OAS Platform
Classifications
CWE-319, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 5, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 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=18.00.0072
  2. Affected versionversion=v18.00.0072

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Open Automation Software · OAS Platformversion=18.00.0072; version=v18.00.0072

Published CVSS scores

8.1Cisco TalosCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-319Cleartext Transmission of Sensitive Information
T1040Network Sniffing

Public exploit references

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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