What is CVE-2021-44158?

CVE-2021-44158 is a high-severity vulnerability in ASUS Rt-Ax56u, classified under Stack-based Buffer Overflow. CVSS score: 8.0/10. Published 2022-01-03.

How severe is CVE-2021-44158?

High severity. CVSS v3 base score is 8.0 out of 10.

Is CVE-2021-44158 known to be exploited?

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

Buffer overflow in ASUS Rt-Ax56u

CVE-2021-44158

ASUS RT-AX56U Wi-Fi Router is vulnerable to stack-based buffer overflow due to improper validation for httpd parameter length. An authenticated local area network attacker can launch arbitrary code execution to control the system or disrupt service.

Vulnerability class: Buffer Overflow

Published 2022-01-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (51.4th percentile), scored 2026-10-20.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.4% 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

ASUS Rt-Ax56u — versions 3.0.0.4.386.44266
ASUS Rt-Ax56u Firmware — versions 3.0.0.4.386.44266

Weakness classification (CWE)

Public proof-of-concept exploits

References

www.twcert.org.tw/tw/cp-132-5431-d23be-1.html (Third Party Advisory)

Frequently asked questions

What is CVE-2021-44158?: CVE-2021-44158 is a high-severity vulnerability in ASUS Rt-Ax56u, classified under Stack-based Buffer Overflow. CVSS score: 8.0/10. Published 2022-01-03.
How severe is CVE-2021-44158?: High severity. CVSS v3 base score is 8.0 out of 10.
Is CVE-2021-44158 known to be exploited?: 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.