CVE-2020-8476Network attack vector

Unauthenticated license reassignment via crafted web-service messages

Published Apr 29, 2020 · Updated Aug 4, 2024

Improper input validation in ABB Central Licensing System 5.1 through 6.1 allows remote attackers to alter node license assignments. The CLS web service accepts specially crafted messages without sufficient input validation or access restrictions and applies attacker-controlled license assignments. Network access to a client-server CLS installation is required; standalone installations are unaffected, and altered assignments can deny licenses to legitimate nodes.

CVSS severity5.3
Medium
EPSS probability1.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in ABB Central Licensing System 5.1 through 6.1 allows remote attackers to alter node license assignments. The CLS web service accepts specially crafted messages without sufficient input validation or access restrictions and applies attacker-controlled license assignments. Network access to a client-server CLS installation is required; standalone installations are unaffected, and altered assignments can deny licenses to legitimate nodes.

The record

CVE
CVE-2020-8476
Published
Apr 29, 2020
Updated
Aug 4, 2024
Vendor
ABB
Product
Composer CTK
Classifications
CWE-20, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 29, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=6.1
  2. Affected versionversion=6.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ABB · Composer CTKversion=6.1; version=6.2
ABB · ABB Ability System 800xAversion=5.1; version=6.0; version=6.1
ABB · OPC Data Linkversion=2.1; version=2.2
ABB · Symphony Plus S+ Operationsversion=3 <=3.2
ABB · Symphony Plus S+ Engineeringversion=1.1 <=2.2
ABB · OPC Server for Mod 300 (non-800xA)version=1.4
ABB · Harmony OPC Server Standaloneversion=6.0; version=6.1; version=7.0
ABB · Advant OCS Control Builder Aversion=1.3; version=1.4
ABB · Composer Harmonyversion=5.1; version=6.0; version=6.1
ABB · AdvaBuildversion=3.7 SP1; version=3.7 SP2
ABB · Advant OCS AC 100 OPS Serverversion=5.1; version=6.0; version=6.1
ABB · ABB Ability SCADAvantageversion=5.1 <unspecified; version=unspecified <=5.6.5
ABB · Compact HMIversion=5.1; version=6.0
ABB · Knowledge Managerversion=8.0; version=9.0; version=9.1
ABB · Composer Melodyversion=5.3; version=6 <=6.3
ABB · Manufacturing Operations Managementversion=1812; version=1909
ABB · Central Licensing Systemversion=5.1 <5*
ABB · Control Builder Safeversion=1.0; version=1.1; version=2.0

Published CVSS scores

4.9Asea Brown Boveri Ltd. (ABB)CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:W/RC:C
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
5.3Asea Brown Boveri Ltd. (ABB)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/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-20Improper Input Validation
T1210Exploitation of Remote Services

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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