CVE-2023-36355Public exploitNetwork attack vector

Service interruption via unchecked ipStart buffer copy

Published Jun 22, 2023 · Updated Dec 2, 2024

Buffer overflow in the IPv6 WAN handler in TP-Link TL-WR940N version 4 allows remote authenticated users to interrupt router service. The /userRpm/WanDynamicIpV6CfgRpm handler copies an oversized ipStart query value beyond its destination buffer while processing a crafted GET request. Low-privileged access to the web management interface is required, and the published impact is denial of service rather than demonstrated code execution.

CVSS severity9.9
Critical
EPSS probability31.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in the IPv6 WAN handler in TP-Link TL-WR940N version 4 allows remote authenticated users to interrupt router service. The /userRpm/WanDynamicIpV6CfgRpm handler copies an oversized ipStart query value beyond its destination buffer while processing a crafted GET request. Low-privileged access to the web management interface is required, and the published impact is denial of service rather than demonstrated code execution.

The record

CVE
CVE-2023-36355
Published
Jun 22, 2023
Updated
Dec 2, 2024
Vendor
TP-Link Systems Inc.
Product
TL-WR940N
Classifications
CWE-120, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 2, 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=4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

TP-Link Systems Inc. · TL-WR940Nversion=4

Published CVSS scores

9.9NIST NVDCVSS:3.1/AV:N/AC:L/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
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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