CVE-2009-0635

Severity: high (CVSS 7.1 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2009-03-27 · updated 2026-06-16
Weakness: CWE-399

Description

Memory leak in the Cisco Tunneling Control Protocol (cTCP) encapsulation feature in Cisco IOS 12.4, when an Easy VPN (aka EZVPN) server is enabled, allows remote attackers to cause a denial of service (memory consumption and device crash) via a sequence of TCP packets.

Affected products

Cisco IOS: 12.4t, 12.4xz, 12.4ya

References

http://secunia.com/advisories/34438
http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90459.shtml
http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90469.shtml
http://www.securityfocus.com/bid/34246
http://www.securitytracker.com/id?1021895
http://www.vupen.com/english/advisories/2009/0851
https://exchange.xforce.ibmcloud.com/vulnerabilities/49417
http://secunia.com/advisories/34438
http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90459.shtml
http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90469.shtml
http://www.securityfocus.com/bid/34246
http://www.securitytracker.com/id?1021895

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