CVE-2020-8479Network attack vector

File disclosure and license interruption via XXE

Published Apr 29, 2020 · Updated Aug 4, 2024

XML external entity injection in ABB Central Licensing System allows remote attackers to read files or interrupt license handling. The CLS Web Service passes crafted XML to a processor that resolves external entities declared in the DTD, permitting references to server or network files. Exploitation requires access to the protected system network; the bounded effects are file access and disrupted license distribution.

CVSS severity9.4
Critical
EPSS probability2.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XML external entity injection in ABB Central Licensing System allows remote attackers to read files or interrupt license handling. The CLS Web Service passes crafted XML to a processor that resolves external entities declared in the DTD, permitting references to server or network files. Exploitation requires access to the protected system network; the bounded effects are file access and disrupted license distribution.

The record

CVE
CVE-2020-8479
Published
Apr 29, 2020
Updated
Aug 4, 2024
Vendor
ABB
Product
Composer CTK
Classifications
CWE-91, 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

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=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

8.4ABBCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L/E:P/RL:O/RC:C
9.4ABBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

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 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-91XML Injection (aka Blind XPath Injection)
T1210Exploitation of Remote Services

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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