CVE-2022-40069Public exploitNetwork attack vector

HTTP service interruption via unbounded time-zone parsing

Published Sep 19, 2022 · Updated Aug 3, 2024

Stack-based buffer overflow in Tenda AC21 firmware 16.03.08.15 allows remote attackers to interrupt the HTTP service. The fromSetSysTime handler passes the timeZone form value to sub_496104, where sscanf writes parsed data into stack variables without a length bound. A crafted POST to /goform/SetSysTimeCfg reaches the flaw without user interaction and causes denial of service against router web management.

CVSS severity7.5
High
EPSS probability0.99%
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 Tenda AC21 firmware 16.03.08.15 allows remote attackers to interrupt the HTTP service. The fromSetSysTime handler passes the timeZone form value to sub_496104, where sscanf writes parsed data into stack variables without a length bound. A crafted POST to /goform/SetSysTimeCfg reaches the flaw without user interaction and causes denial of service against router web management.

The record

CVE
CVE-2022-40069
Published
Sep 19, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 19, 2022CVE 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?

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
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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