CVE-2023-30306

TCP session hijacking via permissive NAT tracking

Published May 28, 2024 · Updated Feb 13, 2025

TCP session hijacking in Mercury X30G and YR1800XG routers allows attackers on the same Wi-Fi network to interrupt victim connections. Their NAT implementations preserve source ports, accept spoofed traffic without strict reverse-path validation, and fail to track TCP windows, so forged reset and data packets can replace a victim mapping and reveal live sequence numbers. Access to the victim's Wi-Fi network is required; a successful attack can close a TCP session, reroute inbound packets, or corrupt unencrypted traffic.

CVSS severity4.3
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

TCP session hijacking in Mercury X30G and YR1800XG routers allows attackers on the same Wi-Fi network to interrupt victim connections. Their NAT implementations preserve source ports, accept spoofed traffic without strict reverse-path validation, and fail to track TCP windows, so forged reset and data packets can replace a victim mapping and reveal live sequence numbers. Access to the victim's Wi-Fi network is required; a successful attack can close a TCP session, reroute inbound packets, or corrupt unencrypted traffic.

The record

CVE
CVE-2023-30306
Published
May 28, 2024
Updated
Feb 13, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1557, T1498
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. May 28, 2024CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 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 vectoradjacent
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1557Adversary-in-the-Middle
T1498Network Denial of Service

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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