What is CVE-2021-46901?

CVE-2021-46901 is a high-severity vulnerability in Cetic Cetic-6lbr, classified under Out-of-bounds Write. CVSS score: 7.5/10. Published 2023-12-31.

How severe is CVE-2021-46901?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2021-46901 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Cetic Cetic-6lbr

CVE-2021-46901

examples/6lbr/apps/6lbr-webserver/httpd.c in CETIC-6LBR (aka 6lbr) 1.5.0 has a strcat stack-based buffer overflow via a request for a long URL over a 6LoWPAN network.

Vulnerability class: Buffer Overflow

Published 2023-12-31 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (50.0th percentile), scored 2026-10-08.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 50.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Cetic Cetic-6lbr — versions 1.5.0

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

DiRaltvein/memory-corruption-examples

References

github.com/cetic/6lbr/issues/414 (Exploit, Issue Tracking, Vendor Advisory)
github.com/cetic/6lbr/blob/c3092a1ccc6b6b0e668f33f6f4b2d6967975d664/examples/6l… (Patch)

Frequently asked questions

What is CVE-2021-46901?: CVE-2021-46901 is a high-severity vulnerability in Cetic Cetic-6lbr, classified under Out-of-bounds Write. CVSS score: 7.5/10. Published 2023-12-31.
How severe is CVE-2021-46901?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2021-46901 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.