CVE-2021-32457Public exploit

Local privilege escalation via unchecked IOCTL length

Published May 26, 2021 · Updated Aug 3, 2024

Stack-based buffer overflow in Trend Micro Home Network Security 6.6.604 and earlier allows local users to escalate privileges via a crafted IOCTL. The tdts.ko chrdev_ioctl_handle function passes a 14-bit, user-controlled IOCTL length to __memzero for a smaller fixed-size kernel stack buffer. Exploitation requires prior low-privileged code execution on the station; the demonstrated result is a kernel panic, while privilege escalation is the reported security impact.

CVSS severity7.8
High
EPSS probability0.43%
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 Trend Micro Home Network Security 6.6.604 and earlier allows local users to escalate privileges via a crafted IOCTL. The tdts.ko chrdev_ioctl_handle function passes a 14-bit, user-controlled IOCTL length to __memzero for a smaller fixed-size kernel stack buffer. Exploitation requires prior low-privileged code execution on the station; the demonstrated result is a kernel panic, while privilege escalation is the reported security impact.

The record

CVE
CVE-2021-32457
Published
May 26, 2021
Updated
Aug 3, 2024
Vendor
Trend Micro
Product
Trend Micro Home Network Security
Classifications
CWE-121, CWE-787, T1068, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=6.6.604 and below

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Trend Micro · Trend Micro Home Network Securityversion=6.6.604 and below

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8Cisco TalosCVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
CWE-787Out-of-bounds Write
T1068Exploitation for Privilege Escalation
T1499Endpoint Denial of Service

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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