CVE-2021-44158

Authenticated code execution via unchecked httpd parameter

Published Jan 3, 2022 · Updated Sep 16, 2024

Stack-based buffer overflow in ASUS RT-AX56U firmware 3.0.0.4.386.44266 allows remote authenticated users to execute arbitrary code. The httpd service fails to validate an HTTP parameter length before copying the value into a fixed-size stack buffer. Reachability requires valid router credentials and LAN access; successful exploitation permits system control or a service interruption.

CVSS severity8.0
High
EPSS probability0.68%
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 ASUS RT-AX56U firmware 3.0.0.4.386.44266 allows remote authenticated users to execute arbitrary code. The httpd service fails to validate an HTTP parameter length before copying the value into a fixed-size stack buffer. Reachability requires valid router credentials and LAN access; successful exploitation permits system control or a service interruption.

The record

CVE
CVE-2021-44158
Published
Jan 3, 2022
Updated
Sep 16, 2024
Vendor
ASUSTeK Computer Inc.
Product
RT-AX56U
Classifications
CWE-121, T1210
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 3, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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?

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

  1. Affected versionversion=3.0.0.4.386.44266

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

ASUSTeK Computer Inc. · RT-AX56Uversion=3.0.0.4.386.44266

Published CVSS scores

8.0TWCERT/CCCVSS:3.1/AV:A/AC:L/PR:L/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.

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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)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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