CVE-2021-21903Public exploitNetwork attack vector

Code execution via unbounded CRC field copy

Published Dec 22, 2021 · Updated Aug 3, 2024

Stack-based buffer overflow in Garrett iC Module CMA 5.0 allows remote attackers to control execution via a crafted UDP packet. The check_udp_crc function advances past the final semicolon and uses unbounded strcpy to copy the CRC field into an eight-byte stack buffer. The unauthenticated discovery service on UDP port 6877 is sufficient to overwrite the program counter and crash the CMA process or enable code execution.

CVSS severity9.8
Critical
EPSS probability1.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Garrett iC Module CMA 5.0 allows remote attackers to control execution via a crafted UDP packet. The check_udp_crc function advances past the final semicolon and uses unbounded strcpy to copy the CRC field into an eight-byte stack buffer. The unauthenticated discovery service on UDP port 6877 is sufficient to overwrite the program counter and crash the CMA process or enable code execution.

The record

CVE
CVE-2021-21903
Published
Dec 22, 2021
Updated
Aug 3, 2024
Vendor
Garrett Metal Detectors
Product
iC Module CMA
Classifications
CWE-120, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 22, 2021CVE 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Garrett Metal Detectors iC Module CMA Version 5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Garrett Metal Detectors · iC Module CMAversion=Garrett Metal Detectors iC Module CMA Version 5.0

Published CVSS scores

9.8Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1190Exploit Public-Facing Application

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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