CVE-2005-0068: The original design of ICMP does not require authentication for host-generated ICMP error messages, which make

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MEDIUM 5.0MITIGATE

CVE-2005-0068 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 ICMP does not require authentication for host-generated ICMP error messages, 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-reduction attacks w

Why this priority

EPSS top 1%: 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	54.4% (top 1%)
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-2005-0068?

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

Is CVE-2005-0068 being exploited?

CVE-2005-0068 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-2005-0068 affect?

CVE-2005-0068 affects tcp. Severity is medium (CVSS 5.0). The original design of ICMP does not require authentication for host-generated ICMP error messages, which makes it easier for attackers to forge ICMP error messages for specific TCP connections and cause a denial of service, as demonstrated

How urgent is CVE-2005-0068?

Priority 42/100. EPSS top 1%: very likely to be exploited

Related CVEs

CVE-2005-3675 HIGH 7.8 MITIGATE The Transmission Control Protocol (TCP) allows remote attackers to cause a denial of service (bandwidth consum
CVE-2005-0067 MEDIUM 5.0 MITIGATE The original design of TCP does not require that port numbers be assigned randomly (aka "Port randomization"),
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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