CVE-2022-40071Public exploitNetwork attack vector

Service interruption via unbounded device-name formatting

Published Sep 19, 2022 · Updated Aug 3, 2024

Stack buffer overflow in Tenda AC21 firmware 16.03.08.15 allows remote attackers to interrupt service via a crafted device name. The set_device_name function passes the devName POST parameter to sprintf with the unbounded format string %s;1 and writes the result into a stack buffer. The management HTTP endpoint requires no authentication, and an oversized device name triggers the published denial-of-service condition.

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 buffer overflow in Tenda AC21 firmware 16.03.08.15 allows remote attackers to interrupt service via a crafted device name. The set_device_name function passes the devName POST parameter to sprintf with the unbounded format string %s;1 and writes the result into a stack buffer. The management HTTP endpoint requires no authentication, and an oversized device name triggers the published denial-of-service condition.

The record

CVE
CVE-2022-40071
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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