HIGH
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
Published Mar 27, 2009
7.1
HIGHCVSS 2.0
EPSS 2.51%
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
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
7.1 HIGH NVD
AV:N/AC:M/Au:N/C:N/I:N/A:C
Access Vector Network
Access Complexity Medium
Authentication None
Confidentiality Impact None
Integrity Impact None
Availability Impact Complete
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
2.51% 0.02508
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
EPSS probability 0.02508
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (9 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 2.51% (0.02508) | 84.21th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.51% (0.02508) | 82.64th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.93% (0.00934) | 74.55th | v4 (v2025.03.14) |
| Dec 12, 2024 | 2.25% (0.02254) | 89.98th | v3 (v2023.03.01) |
| Mar 7, 2023 | 2.09% (0.02090) | 87.33th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.32% (0.01319) | 71.27th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.32% (0.01319) | 71.23th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.32% (0.01319) | 69.22th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.32% (0.01319) | 44.98th | v2 (v2022.01.01) |
Weaknesses (1)
References (7)
- http://secunia.com/advisories/34438 third-party-advisoryx_refsource_SECUNIAVendor Advisory
- http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90459.shtml vendor-advisoryx_refsource_CISCOPatchVendor Advisory
- http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90469.shtml x_refsource_CONFIRMPatchVendor Advisory
- http://www.securityfocus.com/bid/34246 vdb-entryx_refsource_BID
- http://www.securitytracker.com/id?1021895 vdb-entryx_refsource_SECTRACK
- http://www.vupen.com/english/advisories/2009/0851 vdb-entryx_refsource_VUPENVendor Advisory
- https://exchange.xforce.ibmcloud.com/vulnerabilities/49417 vdb-entryx_refsource_XF
| Link | Providers | Tags |
|---|---|---|
| http://secunia.com/advisories/34438 | third-party-advisoryx_refsource_SECUNIAVendor Advisory | |
| http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90459.shtml | vendor-advisoryx_refsource_CISCOPatchVendor Advisory | |
| http://www.cisco.com/en/US/products/products_security_advisory09186a0080a90469.shtml | x_refsource_CONFIRMPatchVendor Advisory | |
| http://www.securityfocus.com/bid/34246 | vdb-entryx_refsource_BID | |
| http://www.securitytracker.com/id?1021895 | vdb-entryx_refsource_SECTRACK | |
| http://www.vupen.com/english/advisories/2009/0851 | vdb-entryx_refsource_VUPENVendor Advisory | |
| https://exchange.xforce.ibmcloud.com/vulnerabilities/49417 | vdb-entryx_refsource_XF |
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner cisco
Published Mar 27, 2009
Updated Aug 7, 2024
Reserved Feb 18, 2009
Link CVE-2009-0635
CISA Vulnrichment
Updated n/a