A vulnerability in the TCP normalizer of Cisco Adaptive Security Appliance (ASA) Software (8.0 through 8.7 and 9.0 through 9.6) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause Cisco ASA and FTD to drop any further incoming traffic on all interfaces, resulting in a denial of service (DoS) condition
Published Apr 20, 2017
4.0
MEDIUMCVSS 3.0
EPSS 1.71%
Description
A vulnerability in the TCP normalizer of Cisco Adaptive Security Appliance (ASA) Software (8.0 through 8.7 and 9.0 through 9.6) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause Cisco ASA and FTD to drop any further incoming traffic on all interfaces, resulting in a denial of service (DoS) condition. The vulnerability is due to improper limitation of the global out-of-order TCP queue for specific block sizes. An attacker could exploit this vulnerability by sending a large number of unique permitted TCP connections with out-of-order segments. An exploit could allow the attacker to exhaust available blocks in the global out-of-order TCP queue, causing the dropping of any further incoming traffic on all interfaces and resulting in a DoS condition. Cisco Bug IDs: CSCvb46321.
Affected products
- Vendor n/a Product Cisco ASA Software and Cisco FTD Software Defaultn/a
- Version Cisco ASA Software and Cisco FTD SoftwareStatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/a | Cisco ASA Software and Cisco FTD Software | n/a |
|
- 8.0.1.2
- 8.0.2
- 8.0.2.11
- 8.0.2.15
- 8.0.3
- 8.0.3.6
- 8.0.3.12
- 8.0.3.19
- 8.0.4
- 8.0.4.3
- 8.0.4.9
- 8.0.4.16
- 8.0.4.23
- 8.0.4.25
- 8.0.4.28
- 8.0.4.31
- 8.0.4.32
- 8.0.4.33
- 8.0.5
- 8.0.5.20
- 8.0.5.23
- 8.0.5.25
- 8.0.5.27
- 8.0.5.28
- 8.0.5.31
- 8.1.0.104
- 8.1.1
- 8.1.1.6
- 8.1.2
- 8.1.2.13
- 8.1.2.15
- 8.1.2.16
- 8.1.2.19
- 8.1.2.23
- 8.1.2.24
- 8.1.2.49
- 8.1.2.50
- 8.1.2.55
- 8.1.2.56
- 8.2.0.45
- 8.2.1
- 8.2.1.11
- 8.2.2
- 8.2.2.9
- 8.2.2.10
- 8.2.2.12
- 8.2.2.16
- 8.2.2.17
- 8.2.3
- 8.2.4
- 8.2.4.1
- 8.2.4.4
- 8.2.5
- 8.2.5.13
- 8.2.5.22
- 8.2.5.26
- 8.2.5.33
- 8.2.5.40
- 8.2.5.41
- 8.2.5.46
- 8.2.5.48
- 8.2.5.50
- 8.2.5.52
- 8.2.5.55
- 8.2.5.57
- 8.2.5.59
- 8.3.1
- 8.3.1.1
- 8.3.1.4
- 8.3.1.6
- 8.3.2
- 8.3.2.4
- 8.3.2.13
- 8.3.2.23
- 8.3.2.25
- 8.3.2.31
- 8.3.2.33
- 8.3.2.34
- 8.3.2.37
- 8.3.2.39
- 8.3.2.40
- 8.3.2.41
- 8.3.2.44
- 8.4.0
- 8.4.1
- 8.4.1.3
- 8.4.1.11
- 8.4.2
- 8.4.2.1
- 8.4.2.8
- 8.4.3
- 8.4.3.8
- 8.4.3.9
- 8.4.4
- 8.4.4.1
- 8.4.4.3
- 8.4.4.5
- 8.4.4.9
- 8.4.5
- 8.4.5.6
- 8.4.6
- 8.4.7
- 8.4.7.3
- 8.4.7.15
- 8.4.7.22
- 8.4.7.23
- 8.4.7.26
- 8.4.7.28
- 8.4.7.29
- 8.5.1
- 8.5.1.1
- 8.5.1.6
- 8.5.1.7
- 8.5.1.14
- 8.5.1.17
- 8.5.1.18
- 8.5.1.19
- 8.5.1.21
- 8.5.1.24
- 8.6.1
- 8.6.1.1
- 8.6.1.2
- 8.6.1.5
- 8.6.1.10
- 8.6.1.12
- 8.6.1.13
- 8.6.1.14
- 8.6.1.17
- 8.7.1
- 8.7.1.1
- 8.7.1.3
- 8.7.1.4
- 8.7.1.7
- 8.7.1.8
- 8.7.1.11
- 8.7.1.13
- 8.7.1.16
- 8.7.1.17
- 9.0.1
- 9.0.2
- 9.0.2.10
- 9.0.3
- 9.0.3.6
- 9.0.3.8
- 9.0.4
- 9.0.4.1
- 9.0.4.5
- 9.0.4.7
- 9.0.4.17
- 9.0.4.20
- 9.0.4.24
- 9.0.4.26
- 9.0.4.29
- 9.0.4.33
- 9.0.4.35
- 9.0.4.37
- 9.0.4.40
- 9.0.4.42
- 9.1\(7\)4
- 9.1\(7\)6
- 9.1\(7\)7
- 9.1\(7\)9
- 9.1\(7\)11
- 9.1\(7\)12
- 9.1.1
- 9.1.1.4
- 9.1.2
- 9.1.2.8
- 9.1.3
- 9.1.3.2
- 9.1.4
- 9.1.4.5
- 9.1.5
- 9.1.5.10
- 9.1.5.12
- 9.1.5.15
- 9.1.5.21
- 9.1.6
- 9.1.6.1
- 9.1.6.4
- 9.1.6.6
- 9.1.6.8
- 9.1.6.10
- 9.2\(0.0\)
- 9.2\(0.104\)
- 9.2\(3.1\)
- 9.2.1
- 9.2.2
- 9.2.2.4
- 9.2.2.7
- 9.2.2.8
- 9.2.3
- 9.2.3.3
- 9.2.3.4
- 9.2.4
- 9.2.4.2
- 9.2.4.4
- 9.2.4.8
- 9.2.4.10
- 9.2.4.13
- 9.2.4.14
- 9.2.4.16
- 9.2.4.17
- 9.3\(1.50\)
- 9.3\(1.105\)
- 9.3\(2.100\)
- 9.3\(2.243\)
- 9.3.1
- 9.3.1.1
- 9.3.2
- 9.3.2.2
- 9.3.3
- 9.3.3.1
- 9.3.3.2
- 9.3.3.5
- 9.3.3.6
- 9.3.3.9
- 9.3.3.10
- 9.3.3.11
- 9.3.5
- 9.4.0.115
- 9.4.1
- 9.4.1.1
- 9.4.1.2
- 9.4.1.3
- 9.4.1.5
- 9.4.2
- 9.4.2.3
- 9.4.3
- 9.4.3.3
- 9.4.3.4
- 9.4.3.6
- 9.4.3.8
- 9.4.3.11
- 9.4.3.12
- 9.4.4
- 9.5.1
- 9.5.2
- 9.5.2.6
- 9.5.2.10
- 9.5.2.14
- 9.5.3
- 9.5.3.2
- 9.5.3.3
- 9.6.0
- 9.6.1
- 9.6.1.3
- 9.6.1.5
- 9.6.1.10
- 9.6.2
- 9.6.2.1
- 9.6.2.2
- 9.6.2.3
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L
AV:N/AC:M/Au:N/C:N/I:N/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Table of values (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.71% (0.01711) | 76.52th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.71% (0.01711) | 74.30th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.39% (0.00388) | 57.85th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.22% (0.00221) | 61.16th | v3 (v2023.03.01) |
| Jun 14, 2024 | 0.22% (0.00221) | 60.44th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.22% (0.00221) | 58.43th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.14% (0.01136) | 59.45th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.14% (0.01136) | 34.23th | v2 (v2022.01.01) |
| Feb 3, 2022 | 1.30% (0.01300) | 31.12th | v5 (v2026.06.15) |
| Apr 14, 2021 | 1.30% (0.01300) | 0.00th | v1 |
References (3)
- http://www.securityfocus.com/bid/97923 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1038329 vdb-entryx_refsource_SECTRACK
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170419-asa-norm x_refsource_CONFIRMVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| http://www.securityfocus.com/bid/97923 | vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry | |
| http://www.securitytracker.com/id/1038329 | vdb-entryx_refsource_SECTRACK | |
| https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170419-asa-norm | x_refsource_CONFIRMVendor Advisory |
Change history (0)
No recorded changes yet.