The original design of TCP does not check that the TCP Acknowledgement number in an ICMP error message generated by an intermediate router is within the range of possible values for data that has already been acknowledged (aka "TCP acknowledgement number checking"), 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 with forged ICMP messages that cause the Path MTU to be reduced. NOTE: CVE-2004-0790, CVE-2004-0791, and CVE-2004-1060 have been SPLIT based on different attacks; CVE-2005-0065, CVE-2005-0066, CVE-2005-0067, and CVE-2005-0068 are related identifiers that are SPLIT based on the underlying vulnerability. While CVE normally SPLITs based on vulnerability, the attack-based identifiers exist due to the variety and number of affected implementations and solutions that address the attacks instead of the underlying vulnerabilities.
Conclusion & alert: CVE-2005-0066 is rated Moderate Risk (58.3/100): CVSS Medium severity, with high exploitation likelihood (EPSS 10.74%, 95th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +9.51% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 1.23% | 10.74% | +9.51% |
| 2 | 2025-07-28 | 0.48% | 1.23% | +0.75% |
| 3 | 2025-03-30 | — | 0.48% | — |
Full EPSS history (7 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
suse
|
medium | CVE-2005-0066 severity moderate: SUSE including 9 source package names (kernel-default, kernel-default-base, …), 129 product×package rows across 30 product lines (SUSE Linux Enterprise High Performance Computing 12 SP4, SUSE Linux Enterprise High Performance Computing 12 SP5, … (30 product lines)): Known Not Affected 129. | https://www.suse.com/security/cve/CVE-2005-0066/ |
| URL | Tags |
|---|---|
| http://www.gont.com.ar/drafts/icmp-attacks-against-tcp.html | Vendor Advisory |
| http://www.securityfocus.com/bid/13124 |