Cisco Firepower Threat Defense Software TCP Intercept Bypass Vulnerability
Published Oct 21, 2020
5.8
MEDIUMCVSS 3.1
EPSS 0.94%
Description
A vulnerability in the TCP Intercept functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured Access Control Policies (including Geolocation) and Service Polices on an affected system. The vulnerability exists because TCP Intercept is invoked when the embryonic connection limit is reached, which can cause the underlying detection engine to process the packet incorrectly. An attacker could exploit this vulnerability by sending a crafted stream of traffic that matches a policy on which TCP Intercept is configured. A successful exploit could allow the attacker to match on an incorrect policy, which could allow the traffic to be forwarded when it should be dropped. In addition, the traffic could incorrectly be dropped.
Affected products
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||
|---|---|---|---|---|---|---|
| Cisco | Cisco Firepower Threat Defense Software | n/a |
|
- < 6.4.0.8
- ≥ 6.5.0 · < 6.5.0.4
- ≥ 6.5.0.5 · < 6.6.0
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
No CVSS v3.0 score for this CVE.
AV:N/AC:M/Au:N/C:N/I:P/A:N
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Nov 13, 2024 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
Table of values (12 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 0.94% (0.00939) | 59.56th | v5 (v2026.06.15) |
| Sep 20, 2026 | 0.94% (0.00939) | 59.37th | v5 (v2026.06.15) |
| Jul 20, 2024 | 0.13% (0.00126) | 47.88th | v3 (v2023.03.01) |
| Sep 3, 2023 | 0.13% (0.00126) | 46.55th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.11% (0.00111) | 42.60th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.05% (0.01055) | 52.13th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.05% (0.01055) | 48.43th | v2 (v2022.01.01) |
| Feb 4, 2022 | 4.50% (0.04499) | 74.08th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.30% (0.02304) | 53.71th | v1 |
| Jan 6, 2022 | 2.30% (0.02304) | 53.25th | v1 |
| Jan 5, 2022 | 0.52% (0.00523) | 33.47th | v5 (v2026.06.15) |
| Apr 14, 2021 | 0.52% (0.00523) | 0.00th | v1 |
References (1)
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-tcp-intercept-bypass-xG9M3PbY vendor-advisoryx_refsource_CISCOVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-tcp-intercept-bypass-xG9M3PbY | vendor-advisoryx_refsource_CISCOVendor Advisory |
Change history (0)
No recorded changes yet.