CVE-2023-0426Network attack vector

Controller reboot via malformed HTTP message

Published Aug 7, 2023 · Updated Nov 7, 2024

Stack-based buffer overflow in ABB Freelance AC 700F and AC 900F controllers allows remote attackers to stop the controller over HTTP. The embedded webserver insufficiently validates a specially crafted HTTP message before processing it in a stack buffer. Network access and an enabled webserver are required; exploitation can reboot or stop the controller.

CVSS severity8.6
High
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in ABB Freelance AC 700F and AC 900F controllers allows remote attackers to stop the controller over HTTP. The embedded webserver insufficiently validates a specially crafted HTTP message before processing it in a stack buffer. Network access and an enabled webserver are required; exploitation can reboot or stop the controller.

The record

CVE
CVE-2023-0426
Published
Aug 7, 2023
Updated
Nov 7, 2024
Vendor
GENEREX SYSTEMS Computervertriebsgesellschaft mbH
Product
ABB Freelance AC 900F Controller
Classifications
CWE-121, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 7, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <=Freelance 2013
  2. Affected versionversion=0 <=Freelance 2013SP1
  3. Affected versionversion=0 <=Freelance 2016
  4. Affected versionversion=0 <=Freelance 2016SP1
  5. Affected versionversion=0 <=Freelance 2019
  6. Affected versionversion=0 <=Freelance 2019 SP1
  7. Affected versionversion=0 <=Freelance 2019 SP1 FP1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GENEREX SYSTEMS Computervertriebsgesellschaft mbH · ABB Freelance AC 900F Controllerversion=0 <=Freelance 2013; version=0 <=Freelance 2013SP1; version=0 <=Freelance 2016; version=0 <=Freelance 2016SP1; version=0 <=Freelance 2019; version=0 <=Freelance 2019 SP1; version=0 <=Freelance 2019 SP1 FP1
GENEREX SYSTEMS Computervertriebsgesellschaft mbH · ABB Freelance AC 700F Controllerversion=0 <=Freelance 2013; version=0 <=Freelance 2013SP1; version=0 <=Freelance 2016; version=0 <=Freelance 2016SP1; version=0 <=Freelance 2019; version=0 <=Freelance 2019 SP1; version=0 <=Freelance 2019 SP1 FP1; version=9.0;0 <=V9.2 SP2; version=9.0.0 <=V9.2 SP2

Published CVSS scores

8.6Asea Brown Boveri Ltd. (ABB)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
7.5Asea Brown Boveri Ltd. (ABB)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H/E:U/RL:O/RC:C
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.

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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 exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499.004Application or System Exploitation

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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