What’s Vulnerable › Vulnerabilities

CVE-2006-3906

• Severity: medium (CVSS 5.0 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 6.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2006-07-27 · updated 2026-06-16

Description

Internet Key Exchange (IKE) version 1 protocol, as implemented on Cisco IOS, VPN 3000 Concentrators, and PIX firewalls, allows remote attackers to cause a denial of service (resource exhaustion) via a flood of IKE Phase-1 packets that exceed the session expiration rate. NOTE: it has been argued that this is due to a design weakness of the IKE version 1 protocol, in which case other vendors and implementations would also be affected.

Affected products

• Cisco ASA Software: 7.0, 7.0(4), 7.0(5), 7.0.1.4, 7.0.4.3, 7.1(2)
• Cisco IOS: all versions
• Cisco Pix Asa Ids: all versions
• Cisco Pix Firewall: 6.2.2_.111, 6.2.3_(110), 6.3.3_(133), 6.3.5_(112)
• Cisco Pix Firewall 501: all versions
• Cisco Pix Firewall 506: all versions
• Cisco Pix Firewall 515: all versions
• Cisco Pix Firewall 515E: all versions
• Cisco Pix Firewall 520: all versions
• Cisco Pix Firewall 525: all versions
• Cisco Pix Firewall 535: all versions
• Cisco Pix Firewall Software: 2.7, 3.0, 3.1, 4.0, 4.1(6), 4.1(6b) (+51)
• Cisco Secure Pix Firewall: all versions
• Cisco Vpn 3000 Concentrator Series Software: 2.0, 2.5.2.a, 2.5.2.b, 2.5.2.c, 2.5.2.d, 2.5.2.f (+42)
• Cisco Vpn 3001 Concentrator: all versions
• Cisco Vpn 3005 Concentrator Software: 4.0.1
• Cisco Vpn 3015 Concentrator: all versions
• Cisco Vpn 3020 Concentrator: all versions
• Cisco Vpn 3030 Concentator: 4.7(rel), 4.7.1, 4.7.1.f, 4.7.2, 4.7.2.a, 4.7.2.f
• Cisco Vpn 3060 Concentrator: all versions
• Cisco Vpn 3080 Concentrator: all versions

References

• http://archives.neohapsis.com/archives/bugtraq/2006-07/0531.html
• http://securityreason.com/securityalert/1293
• http://securitytracker.com/id?1016582
• http://www.cisco.com/en/US/tech/tk583/tk372/tsd_technology_security_response09186a00806f33d4.html
• http://www.nta-monitor.com/posts/2006/07/cisco-concentrator-dos.html
• http://www.osvdb.org/29068
• http://www.securityfocus.com/archive/1/441203/100/0/threaded
• http://www.securityfocus.com/bid/19176
• https://exchange.xforce.ibmcloud.com/vulnerabilities/27972
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5299
• http://archives.neohapsis.com/archives/bugtraq/2006-07/0531.html
• http://securityreason.com/securityalert/1293

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