CVE-2005-0067: The original design of TCP does not require that port numbers be assigned randomly (aka "Port randomization"),

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MEDIUM 5.0MITIGATE

CVE-2005-0067 is a medium-severity flaw (CVSS 5.0) affecting tcp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The original design of TCP does not require that port numbers be assigned randomly (aka "Port randomization"), which makes it easier for attackers to forge ICMP error messages for specific TCP connections and cause a denial of service, as demonstrated using (1) blind connection-reset attacks with forged "Destination Unreachable" messages, (2) blind throughput-reduction attacks with forged "Source Quench" messages, or (3) blind throughput-reductio

Why this priority

EPSS top 4%: very likely to be exploited

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	13.5% (top 4%)
CISA exploited list	No
Published	2004-12-22
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: tcp

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2004-12-22 05:00 UTCPublished CVE record published
2026-06-16 22:10 UTCUpdated Record last modified

tcp tcp MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy tcp || rpm -q tcp || tcp --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2005-0067?

tcp: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2005-0067 being exploited?

CVE-2005-0067 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2005-0067 affect?

CVE-2005-0067 affects tcp. Severity is medium (CVSS 5.0). The original design of TCP does not require that port numbers be assigned randomly (aka "Port randomization"), which makes it easier for attackers to forge ICMP error messages for specific TCP connections and cause a denial of service, as d

How urgent is CVE-2005-0067?

Priority 42/100. EPSS top 4%: very likely to be exploited

Related CVEs

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CVE-2005-0068 MEDIUM 5.0 MITIGATE The original design of ICMP does not require authentication for host-generated ICMP error messages, which make
CVE-2005-0066 MEDIUM 5.0 MITIGATE The original design of TCP does not check that the TCP Acknowledgement number in an ICMP error message generat
CVE-2005-0065 HIGH 10.0 MITIGATE The original design of TCP does not check that the TCP sequence number in an ICMP error message is within the
CVE-2004-1060 MEDIUM 5.0 MITIGATE MITIGATE Multiple TCP/IP and ICMP implementations, when using Path MTU (PMTU) discovery (PMTUD), allow remote attackers

References

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