CVE-2023-4041Public exploitNetwork attack vector

Persistent code execution via unchecked GBL tag length

Published Aug 23, 2023 · Updated Oct 3, 2024

Stack buffer overflow in Silicon Labs Gecko Bootloader before 4.2.4 and 4.3.0 through 4.3.1 allows remote attackers to execute code. parser_parseApplicationInfo passes an attacker-controlled GBL Application Info tag length to gbl_getData, which copies into a 64-byte stack buffer without validating the length. An OTA-enabled device accepting unencrypted GBL uploads is exposed; exploitation installs persistent unsigned firmware despite Secure Boot.

CVSS severity9.8
Critical
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in Silicon Labs Gecko Bootloader before 4.2.4 and 4.3.0 through 4.3.1 allows remote attackers to execute code. parser_parseApplicationInfo passes an attacker-controlled GBL Application Info tag length to gbl_getData, which copies into a 64-byte stack buffer without validating the length. An OTA-enabled device accepting unencrypted GBL uploads is exposed; exploitation installs persistent unsigned firmware despite Secure Boot.

The record

CVE
CVE-2023-4041
Published
Aug 23, 2023
Updated
Oct 3, 2024
Vendor
Silicon Laboratories
Product
Gecko Bootloader
Classifications
CWE-787, CWE-120, CWE-913
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <4.3.1
  2. Affected versionversion=0 <4.3.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Silicon Laboratories · Gecko Bootloaderversion=0 <4.3.1; version=0 <4.3.2
Sigma Designs · Gecko Bootloaderversion=0 <4.2.4; version=0 <4.3.1

Published CVSS scores

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
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-913Improper Control of Dynamically-Managed Code Resources

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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