CVE-2022-43677Public exploit

Service crash via zero-length bit-string underflow

Published Oct 24, 2022 · Updated Aug 3, 2024

Denial of service in free5GC 3.2.1 allows local users to crash the AMF and NGAP decoders with a malformed NGAP message. GetBitString accepts a zero bit count, subtracts one to derive an end-bit index, and underflows that index before accessing the input buffer. NVD assesses local access and user interaction as prerequisites; successful exploitation interrupts the AMF service without affecting confidentiality or integrity.

CVSS severity5.5
Medium
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in free5GC 3.2.1 allows local users to crash the AMF and NGAP decoders with a malformed NGAP message. GetBitString accepts a zero bit count, subtracts one to derive an end-bit index, and underflows that index before accessing the input buffer. NVD assesses local access and user interaction as prerequisites; successful exploitation interrupts the AMF service without affecting confidentiality or integrity.

The record

CVE
CVE-2022-43677
Published
Oct 24, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 24, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

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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