Is CVE-2008-4609 being actively exploited?

CVE-2008-4609 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2008-4609?

CVE-2008-4609 has a CVSS 2.0 base score of 7.1 (HIGH).

CVE-2008-4609

HIGH · CVSS 7.1EPSS 32.4%EU EUVD

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.

Key facts

CVSS score: 7.1 (v2.0)
Severity: HIGH
CVSS vector: AV:N/AC:M/Au:N/C:N/I:N/A:C
Weakness (CWE): CWE-16
EPSS score: 32.4% (98th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2008-4589)
Published: October 20, 2008
NVD last modified: June 16, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2008-4589 in the EU Vulnerability Database. Last updated in EUVD on August 7, 2024.

View on the EU Vulnerability Database

Affected products

bsd / bsd
bsd / bsd
bsd / bsd
bsd / bsd
bsd / bsd
bsdi / bsd os
bsdi / bsd os
bsdi / bsd os
bsdi / bsd os
bsdi / bsd os
bsdi / bsd os
bsdi / bsd os
bsdi / bsd os
bsdi / bsd os
bsdi / bsd os
bsdi / bsd os
bsdi / bsd os
cisco / catalyst blade switch 3020
cisco / catalyst blade switch 3020 firmware
cisco / catalyst blade switch 3120
cisco / catalyst blade switch 3120 firmware
cisco / catalyst blade switch 3120x
cisco / catalyst blade switch 3120x firmware
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios
cisco / ios

and 950 more…

Certified products that may be affected

11 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

Windows Vista Enhanced Cryptographic Provider (RSAENH) - Microsoft Corporation - FIPS 140 1002 - historical
Windows Vista Enhanced DSS and Diffie-Hellman Cryptographic Provider (DSSENH) - Microsoft Corporation - FIPS 140 1003 - historical
Windows XP Enhanced Cryptographic Provider (RSAENH) - Microsoft Corporation - FIPS 140 989 - historical
Windows XP Enhanced DSS and Diffie-Hellman Cryptographic Provider (DSSENH) - Microsoft Corporation - FIPS 140 990 - historical
Windows Vista Boot Manager (bootmgr) - Microsoft Corporation - FIPS 140 978 - historical

See all 11 in the Security Certifications Explorer.

References

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)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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