CVE-2021-43575: KNX ETS6 through 6.0.0 uses the hard-coded password ETS5Password, with a salt value of Ivan Medvedev, allowing

Routine

MEDIUM 5.5DOWNGRADE

CVE-2021-43575 is a medium-severity flaw (CVSS 5.5) affecting engineering tool software 6. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

KNX ETS6 through 6.0.0 uses the hard-coded password ETS5Password, with a salt value of Ivan Medvedev, allowing local users to read project information, a similar issue to CVE-2021-36799. NOTE: The vendor disputes this because it is not the responsibility of the ETS to securely store cryptographic key material when it is not being exported

Why this priority

Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 75%)
CISA exploited list	No
Weakness	CWE-798
Published	2021-11-09
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: knx

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-11-09 23:15 UTCPublished CVE record published
2026-06-17 04:11 UTCUpdated Record last modified

knx engineering tool software 6 DOWNGRADE

Affected: 6.0.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0.0

1. Check installed version

apt-cache policy engineering-tool-software-6 || rpm -q engineering-tool-software-6 || engineering-tool-software-6 --version

2. No fixed release: DOWNGRADE to a release before 6.0.0 (Debian / Ubuntu)

apt-cache madison engineering-tool-software-6 sudo apt install engineering-tool-software-6=<VERSION_BEFORE_6.0.0> sudo apt-mark hold engineering-tool-software-6

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list engineering-tool-software-6 sudo dnf downgrade engineering-tool-software-6-<VERSION_BEFORE_6.0.0> sudo dnf versionlock add engineering-tool-software-6

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-43575?

engineering tool software 6: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-43575 being exploited?

CVE-2021-43575 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-43575 affect?

CVE-2021-43575 affects engineering tool software 6. Severity is medium (CVSS 5.5). KNX ETS6 through 6.0.0 uses the hard-coded password ETS5Password, with a salt value of Ivan Medvedev, allowing local users to read project information, a similar issue to CVE-2021-36799. NOTE: The vendor disputes this because it is not the

How urgent is CVE-2021-43575?

Priority 31/100. Public exploit reference

References

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