CVE-2008-4609

The TCP implementation in (1) Linux, (2) platforms based on BSD Unix, (3) Microsoft Windows, (4) Cisco products, and probably other operating systems allows remote attackers to cause a denial of service (connection queue exhaustion) via multiple vectors that manipulate information in the TCP state table, as demonstrated by sockstress.

Published: 2008-10-20 Last update: 2026-04-23 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2008-4609 is rated Moderate Risk (58/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.98%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2008-4609

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 2026-05-29 1.71% 1.98% +0.28%
2 2026-05-18 1.88% 1.71% -0.17%
3 2026-02-24 — 1.88% —

Full EPSS history (32 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2008-4609

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 2.0 HIGH
AV:N/AC:M/Au:N/C:N/I:N/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.6 6.9 [email protected]

Weakness enumeration for CVE-2008-4609

OS Trackers for CVE-2008-4609

vendor priority summary link
debian unimportant CVE-2008-4609 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2008-4609
redhat medium — https://access.redhat.com/security/cve/CVE-2008-4609
ubuntu negligible CVE-2008-4609 negligible priority: Ubuntu including 3 source packages (linux, linux-source-2.6.15, linux-source-2.6.22), 15 status rows across 5 suites (dapper, gutsy, hardy, intrepid, upstream): DNE 8, ignored 4, needs-triage 2, needed 1. https://ubuntu.com/security/CVE-2008-4609

NVD evaluator notes for CVE-2008-4609

Impact: The impact of this vulnerability has yet to be determined. The full list of affected platforms is subject to change. The NVD will continue to monitor this vulnerability and adjust the configurations as needed.

Comment: Please see also: http://blog.robertlee.name/2008/10/more-detailed-response-to-gordons-post.html and http://www.curbrisk.com/security-blog/robert-e-lee-discusses-tcp-denial-service-vulnerability-sc-magazine.html

Vendor comments (NVD) for CVE-2008-4609

  • Red Hat (2009-09-08T00:00:00)

    The attacks reported by Outpost24 AB target the design limitations of the TCP protocol. Due to upstreams decision not to release updates, Red Hat do not plan to release updates to resolve these issues however, the effects of these attacks can be reduced via the mitigation methods as written in http://kbase.redhat.com/faq/docs/DOC-18730.

Affected software / configurations for CVE-2008-4609

Vendor Product Version Raw CPE
bsd bsd — cpe:2.3:o:bsd:bsd:-:*:*:*:*:*:*:*
bsd bsd 4.1 cpe:2.3:o:bsd:bsd:4.1:*:*:*:*:*:*:*
bsd bsd 4.2 cpe:2.3:o:bsd:bsd:4.2:*:*:*:*:*:*:*
bsd bsd 4.3 cpe:2.3:o:bsd:bsd:4.3:*:*:*:*:*:*:*
bsd bsd 4.4 cpe:2.3:o:bsd:bsd:4.4:*:*:*:*:*:*:*
bsdi bsd_os — cpe:2.3:o:bsdi:bsd_os:-:*:*:*:*:*:*:*
bsdi bsd_os 1.1 cpe:2.3:o:bsdi:bsd_os:1.1:*:*:*:*:*:*:*
bsdi bsd_os 2.0 cpe:2.3:o:bsdi:bsd_os:2.0:*:*:*:*:*:*:*
bsdi bsd_os 2.0.1 cpe:2.3:o:bsdi:bsd_os:2.0.1:*:*:*:*:*:*:*
bsdi bsd_os 2.1 cpe:2.3:o:bsdi:bsd_os:2.1:*:*:*:*:*:*:*
bsdi bsd_os 3.0 cpe:2.3:o:bsdi:bsd_os:3.0:*:*:*:*:*:*:*
bsdi bsd_os 3.1 cpe:2.3:o:bsdi:bsd_os:3.1:*:*:*:*:*:*:*
bsdi bsd_os 3.2 cpe:2.3:o:bsdi:bsd_os:3.2:*:*:*:*:*:*:*
bsdi bsd_os 4.0 cpe:2.3:o:bsdi:bsd_os:4.0:*:*:*:*:*:*:*
bsdi bsd_os 4.0.1 cpe:2.3:o:bsdi:bsd_os:4.0.1:*:*:*:*:*:*:*
bsdi bsd_os 4.1 cpe:2.3:o:bsdi:bsd_os:4.1:*:*:*:*:*:*:*
bsdi bsd_os 4.2 cpe:2.3:o:bsdi:bsd_os:4.2:*:*:*:*:*:*:*
cisco ios — cpe:2.3:o:cisco:ios:-:*:*:*:*:*:*:*
cisco ios 4.1 cpe:2.3:o:cisco:ios:4.1:*:*:*:*:*:*:*
cisco ios 4.1.1 cpe:2.3:o:cisco:ios:4.1.1:*:*:*:*:*:*:*
cisco ios 4.1.2 cpe:2.3:o:cisco:ios:4.1.2:*:*:*:*:*:*:*
cisco ios 8.2 cpe:2.3:o:cisco:ios:8.2:*:*:*:*:*:*:*
cisco ios 8.3 cpe:2.3:o:cisco:ios:8.3:*:*:*:*:*:*:*
cisco ios 9.0 cpe:2.3:o:cisco:ios:9.0:*:*:*:*:*:*:*
cisco ios 9.1 cpe:2.3:o:cisco:ios:9.1:*:*:*:*:*:*:*
cisco ios 9.14 cpe:2.3:o:cisco:ios:9.14:*:*:*:*:*:*:*
cisco ios 10.0 cpe:2.3:o:cisco:ios:10.0:*:*:*:*:*:*:*
cisco ios 10.3 cpe:2.3:o:cisco:ios:10.3:*:*:*:*:*:*:*
cisco ios 10.3\(3.3\) cpe:2.3:o:cisco:ios:10.3\(3.3\):*:*:*:*:*:*:*
cisco ios 10.3\(3.4\) cpe:2.3:o:cisco:ios:10.3\(3.4\):*:*:*:*:*:*:*
cisco ios 10.3\(4.2\) cpe:2.3:o:cisco:ios:10.3\(4.2\):*:*:*:*:*:*:*
cisco ios 10.3\(4.3\) cpe:2.3:o:cisco:ios:10.3\(4.3\):*:*:*:*:*:*:*
cisco ios 10.3\(16\) cpe:2.3:o:cisco:ios:10.3\(16\):*:*:*:*:*:*:*
cisco ios 10.3\(19a\) cpe:2.3:o:cisco:ios:10.3\(19a\):*:*:*:*:*:*:*
cisco ios 11 cpe:2.3:o:cisco:ios:11:*:*:*:*:*:*:*
cisco ios 11.0 cpe:2.3:o:cisco:ios:11.0:*:*:*:*:*:*:*
cisco ios 11.0\(12\) cpe:2.3:o:cisco:ios:11.0\(12\):*:*:*:*:*:*:*
cisco ios 11.0\(17\) cpe:2.3:o:cisco:ios:11.0\(17\):*:*:*:*:*:*:*
cisco ios 11.0\(17\)bt cpe:2.3:o:cisco:ios:11.0\(17\)bt:*:*:*:*:*:*:*
cisco ios 11.0\(18\) cpe:2.3:o:cisco:ios:11.0\(18\):*:*:*:*:*:*:*
cisco ios 11.0\(20.3\) cpe:2.3:o:cisco:ios:11.0\(20.3\):*:*:*:*:*:*:*
cisco ios 11.0\(22a\) cpe:2.3:o:cisco:ios:11.0\(22a\):*:*:*:*:*:*:*
cisco ios 11.0\(22b\) cpe:2.3:o:cisco:ios:11.0\(22b\):*:*:*:*:*:*:*
cisco ios 11.0\(x\) cpe:2.3:o:cisco:ios:11.0\(x\):*:*:*:*:*:*:*
cisco ios 11.0.12\(a\)bt cpe:2.3:o:cisco:ios:11.0.12\(a\)bt:*:*:*:*:*:*:*
cisco ios 11.1 cpe:2.3:o:cisco:ios:11.1:*:*:*:*:*:*:*
cisco ios 11.1\(5\) cpe:2.3:o:cisco:ios:11.1\(5\):*:*:*:*:*:*:*
cisco ios 11.1\(7\) cpe:2.3:o:cisco:ios:11.1\(7\):*:*:*:*:*:*:*
cisco ios 11.1\(7\)aa cpe:2.3:o:cisco:ios:11.1\(7\)aa:*:*:*:*:*:*:*
cisco ios 11.1\(7\)ca cpe:2.3:o:cisco:ios:11.1\(7\)ca:*:*:*:*:*:*:*
cisco ios 11.1\(9\)ia cpe:2.3:o:cisco:ios:11.1\(9\)ia:*:*:*:*:*:*:*
cisco ios 11.1\(11\) cpe:2.3:o:cisco:ios:11.1\(11\):*:*:*:*:*:*:*
cisco ios 11.1\(12\) cpe:2.3:o:cisco:ios:11.1\(12\):*:*:*:*:*:*:*
cisco ios 11.1\(13\) cpe:2.3:o:cisco:ios:11.1\(13\):*:*:*:*:*:*:*
cisco ios 11.1\(13\)aa cpe:2.3:o:cisco:ios:11.1\(13\)aa:*:*:*:*:*:*:*
cisco ios 11.1\(13\)ca cpe:2.3:o:cisco:ios:11.1\(13\)ca:*:*:*:*:*:*:*
cisco ios 11.1\(13\)ia cpe:2.3:o:cisco:ios:11.1\(13\)ia:*:*:*:*:*:*:*
cisco ios 11.1\(14\) cpe:2.3:o:cisco:ios:11.1\(14\):*:*:*:*:*:*:*
cisco ios 11.1\(15\) cpe:2.3:o:cisco:ios:11.1\(15\):*:*:*:*:*:*:*
cisco ios 11.1\(15\)aa cpe:2.3:o:cisco:ios:11.1\(15\)aa:*:*:*:*:*:*:*
cisco ios 11.1\(15\)ca cpe:2.3:o:cisco:ios:11.1\(15\)ca:*:*:*:*:*:*:*
cisco ios 11.1\(15\)ia cpe:2.3:o:cisco:ios:11.1\(15\)ia:*:*:*:*:*:*:*
cisco ios 11.1\(16\) cpe:2.3:o:cisco:ios:11.1\(16\):*:*:*:*:*:*:*
cisco ios 11.1\(16\)aa cpe:2.3:o:cisco:ios:11.1\(16\)aa:*:*:*:*:*:*:*
cisco ios 11.1\(16\)ia cpe:2.3:o:cisco:ios:11.1\(16\)ia:*:*:*:*:*:*:*
cisco ios 11.1\(17\) cpe:2.3:o:cisco:ios:11.1\(17\):*:*:*:*:*:*:*
cisco ios 11.1\(17\)cc cpe:2.3:o:cisco:ios:11.1\(17\)cc:*:*:*:*:*:*:*
cisco ios 11.1\(17\)ct cpe:2.3:o:cisco:ios:11.1\(17\)ct:*:*:*:*:*:*:*
cisco ios 11.1\(18\) cpe:2.3:o:cisco:ios:11.1\(18\):*:*:*:*:*:*:*
cisco ios 11.1\(20\)aa4 cpe:2.3:o:cisco:ios:11.1\(20\)aa4:*:*:*:*:*:*:*
cisco ios 11.1\(22\) cpe:2.3:o:cisco:ios:11.1\(22\):*:*:*:*:*:*:*
cisco ios 11.1\(24\) cpe:2.3:o:cisco:ios:11.1\(24\):*:*:*:*:*:*:*
cisco ios 11.1\(24a\) cpe:2.3:o:cisco:ios:11.1\(24a\):*:*:*:*:*:*:*
cisco ios 11.1\(24b\) cpe:2.3:o:cisco:ios:11.1\(24b\):*:*:*:*:*:*:*
cisco ios 11.1\(24c\) cpe:2.3:o:cisco:ios:11.1\(24c\):*:*:*:*:*:*:*
cisco ios 11.1\(28a\)ct cpe:2.3:o:cisco:ios:11.1\(28a\)ct:*:*:*:*:*:*:*
cisco ios 11.1\(28a\)ia cpe:2.3:o:cisco:ios:11.1\(28a\)ia:*:*:*:*:*:*:*
cisco ios 11.1\(36\)ca2 cpe:2.3:o:cisco:ios:11.1\(36\)ca2:*:*:*:*:*:*:*
cisco ios 11.1\(36\)ca4 cpe:2.3:o:cisco:ios:11.1\(36\)ca4:*:*:*:*:*:*:*
cisco ios 11.1\(36\)cc2 cpe:2.3:o:cisco:ios:11.1\(36\)cc2:*:*:*:*:*:*:*

References for CVE-2008-4609

URL Tags
http://blog.robertlee.name/2008/10/conjecture-speculation.html Broken Link
http://insecure.org/stf/tcp-dos-attack-explained.html Broken Link
http://lists.immunitysec.com/pipermail/dailydave/2008-October/005360.html Broken Link
http://marc.info/?l=bugtraq&m=125856010926699&w=2 Third Party Advisory
http://searchsecurity.techtarget.com.au/articles/27154-TCP-is-fundamentally-borked Broken Link
http://www.cisco.com/en/US/products/products_security_advisory09186a0080af511d.shtml Broken Link
http://www.cisco.com/en/US/products/products_security_response09186a0080a15120.html Broken Link
http://www.cpni.gov.uk/Docs/tn-03-09-security-assessment-TCP.pdf Broken Link
http://www.mandriva.com/security/advisories?name=MDVSA-2013:150 Broken Link
http://www.oracle.com/technetwork/topics/security/cpujul2012-392727.html Third Party Advisory
http://www.outpost24.com/news/news-2008-10-02.html Broken Link
http://www.us-cert.gov/cas/techalerts/TA09-251A.html Third Party Advisory US Government Resource
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-048 Patch Third Party Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6340 Broken Link
https://www.cert.fi/haavoittuvuudet/2008/tcp-vulnerabilities.html Broken Link
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