CVE-2022-24400: A flaw in the TETRA authentication procecure allows a MITM adversary that can predict the MS challenge RAND2 t

Routine

HIGH 7.5DOWNGRADE

CVE-2022-24400 is a high-severity flaw (CVSS 7.5) affecting tetra\. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw in the TETRA authentication procecure allows a MITM adversary that can predict the MS challenge RAND2 to set session key DCK to zero.

Why this priority

High severity

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

Risk facts

CVSS score	7.5 (High)
Attack vector	Adjacent network
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 80%)
CISA exploited list	No
Weakness	CWE-807, CWE-639
Published	2023-10-19
Last modified	2026-06-17

Publisher (CNA): National Cyber Security Centre Netherlands (NCSC-NL) · Vendor: midnightblue

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

Am I affected?

Timeline

2023-10-19 10:15 UTCPublished CVE record published
2026-06-17 04:31 UTCUpdated Record last modified

midnightblue tetra\ DOWNGRADE

Affected: burst

Fixed in: no fixed release known

Safe to downgrade to: a release before burst

1. Check installed version

apt-cache policy tetra || rpm -q tetra || tetra --version

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

apt-cache madison tetra sudo apt install tetra=<VERSION_BEFORE_burst> sudo apt-mark hold tetra

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

dnf --showduplicates list tetra sudo dnf downgrade tetra-<VERSION_BEFORE_burst> sudo dnf versionlock add tetra

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-2022-24400?

tetra\: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2022-24400 being exploited?

CVE-2022-24400 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-2022-24400 affect?

CVE-2022-24400 affects tetra\. Severity is high (CVSS 7.5). A flaw in the TETRA authentication procecure allows a MITM adversary that can predict the MS challenge RAND2 to set session key DCK to zero.

How urgent is CVE-2022-24400?

Priority 31/100. High severity

Related CVEs

CVE-2022-24404 MEDIUM 5.9 DOWNGRADE Lack of cryptographic integrity check on TETRA air-interface encrypted traffic
CVE-2022-24403 MEDIUM 4.3 DOWNGRADE The TETRA TA61 identity encryption function internally uses a 64-bit value derived exclusively from the SCK (C
CVE-2022-24402 HIGH 8.8 DOWNGRADE The TETRA TEA1 keystream generator implements a key register initialization function that compresses the 80-bi
CVE-2022-24401 HIGH 8.8 DOWNGRADE Adversary-induced keystream re-use on TETRA air-interface encrypted traffic using any TEA keystream generator

References

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