CVE-2023-23306Public exploitNetwork attack vector

Firmware execution hijack via unchecked BurstPayload metadata

Published May 23, 2023 · Updated Jan 31, 2025

Type confusion in Garmin Connect IQ API 2.2.0 through 4.1.7 allows attackers to hijack device firmware execution. Toybox.Ant.BurstPayload.add accepts a negative size or replacement burstDataBlob without correlating their bounds, then writes eight payload bytes at offsets derived from that untrusted metadata. A crafted Connect IQ application must instantiate a subclass and call add; the resulting out-of-bounds write corrupts arbitrary device memory and can redirect firmware control flow.

CVSS severity9.8
Critical
EPSS probability1.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Type confusion in Garmin Connect IQ API 2.2.0 through 4.1.7 allows attackers to hijack device firmware execution. Toybox.Ant.BurstPayload.add accepts a negative size or replacement burstDataBlob without correlating their bounds, then writes eight payload bytes at offsets derived from that untrusted metadata. A crafted Connect IQ application must instantiate a subclass and call add; the resulting out-of-bounds write corrupts arbitrary device memory and can redirect firmware control flow.

The record

CVE
CVE-2023-23306
Published
May 23, 2023
Updated
Jan 31, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 31, 2025Record 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-787Out-of-bounds Write
T1203Exploitation for Client Execution

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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