CVE-2021-46901Public exploitNetwork attack vector

Service crash via unbounded URL concatenation

Published Dec 31, 2023 · Updated Aug 4, 2024

Stack-based buffer overflow in CETIC-6LBR 1.5.0 allows remote attackers to crash its web server via a long URL over 6LoWPAN. The httpd_is_file function copies the web root into a fixed-size stack buffer, then appends the request-derived filename with unbounded strcat. An unauthenticated HTTP request from the 6LoWPAN network is sufficient to trigger stack smashing and interrupt the service.

CVSS severity7.5
High
EPSS probability0.66%
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 CETIC-6LBR 1.5.0 allows remote attackers to crash its web server via a long URL over 6LoWPAN. The httpd_is_file function copies the web root into a fixed-size stack buffer, then appends the request-derived filename with unbounded strcat. An unauthenticated HTTP request from the 6LoWPAN network is sufficient to trigger stack smashing and interrupt the service.

The record

CVE
CVE-2021-46901
Published
Dec 31, 2023
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 31, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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 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
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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