CVE-2023-41603Network attack vector

Remote service exposure via missing IPv6 firewall rules

Published Jan 10, 2024 · Updated Jun 17, 2025

Improper access control in D-Link R15 firmware 1.08.02 and earlier allows remote attackers to reach LAN-only services over IPv6. The WAN interface enables IPv6 by default but applies its firewall access restrictions only to IPv4 traffic, leaving IPv6 listeners exposed. An IPv6-reachable WAN path and a service listening on IPv6 are required; the flaw exposes that service without itself granting code execution.

CVSS severity5.3
Medium
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in D-Link R15 firmware 1.08.02 and earlier allows remote attackers to reach LAN-only services over IPv6. The WAN interface enables IPv6 by default but applies its firewall access restrictions only to IPv4 traffic, leaving IPv6 listeners exposed. An IPv6-reachable WAN path and a service listening on IPv6 are required; the flaw exposes that service without itself granting code execution.

The record

CVE
CVE-2023-41603
Published
Jan 10, 2024
Updated
Jun 17, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-284, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 10, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 2025Record 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

5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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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