CVE-2023-37021

Name: CVE-2023-37021
Creator: NVD / NIST
Published: 2025-01-22T15:15:11.71+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.6/10EPSS 0.75%

Last modified Jun 17, 2026

CVE-2023-37021 is a high-severity vulnerability rated 8.6/10 on the CVSS scale. Open5GS MME version <= 2.6.4 contains an assertion that can be remotely triggered via a malformed ASN.1 packet over the S1AP interface. An attacker may send a `UE Context Modification Failure` message missing a required `MME_UE_S1AP_ID` field to repeatedly crash the MME, resulting in denial of service.. EPSS estimates a 0.75% chance of exploitation in the next 30 days.

Description

Open5GS MME version <= 2.6.4 contains an assertion that can be remotely triggered via a malformed ASN.1 packet over the S1AP interface. An attacker may send a `UE Context Modification Failure` message missing a required `MME_UE_S1AP_ID` field to repeatedly crash the MME, resulting in denial of service.

Metrics

CVSS 3.1

8.6/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS Probability

0.75%

50.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-617

Affected Software

Vendor	Product	Versions
Open5gs	Open5gs	<= 2.6.4

References

https://cellularsecurity.org/ransackedExploit, Technical Description, Third Party Advisory

Timeline

Published: Jan 22, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2023-37021?

How severe is CVE-2023-37021?

CVE-2023-37021 has a CVSS score of 8.6/10 (HIGH severity). The EPSS model estimates a 0.75% probability of exploitation in the next 30 days.

How do I fix CVE-2023-37021?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-37021?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST