A vulnerability in the Secure Sockets Layer (SSL) Virtual Private Network (VPN) Client Certificate Authentication feature for Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to establish an SSL VPN connection and bypass certain SSL certificate verification steps
Published Apr 19, 2018
7.5
HIGHCVSS 3.1
EPSS 2.03%
Description
A vulnerability in the Secure Sockets Layer (SSL) Virtual Private Network (VPN) Client Certificate Authentication feature for Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to establish an SSL VPN connection and bypass certain SSL certificate verification steps. The vulnerability is due to incorrect verification of the SSL Client Certificate. An attacker could exploit this vulnerability by connecting to the ASA VPN without a proper private key and certificate pair. A successful exploit could allow the attacker to establish an SSL VPN connection to the ASA when the connection should have been rejected. This vulnerability affects Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliances (ISA), ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliances (ASAv), Firepower 4110 Security Appliances, Firepower 9300 ASA Security Modules. Cisco Bug IDs: CSCvg40155.
Affected products
- Vendor n/a Product Cisco Adaptive Security Appliance Defaultn/a
- Version Cisco Adaptive Security ApplianceStatusaffectedConstraints-
- 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 Adaptive Security Appliance | n/a |
|
Configuration 1
- ≥ 9.4.4 · ≤ 9.4.4.13
- ≥ 9.5.3.7 · ≤ 9.5.3.9
- ≥ 9.6.2.9 · ≤ 9.6.2.21
- ≥ 9.6.3 · ≤ 9.6.3.17
- 9.4.3.1
- 9.4.3.2
- 9.5.2.7
- 9.5.2.8
Configuration 2
- ≥ 6.0 · ≤ 6.0.1.4
- ≥ 6.1.0 · ≤ 6.1.0.5
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:U/C:N/I:H/A:N
No CVSS v3.0 score for this CVE.
AV:N/AC:L/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 29, 2024 · SSVC 2.0.3
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 (13 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 2.03% (0.02033) | 80.36th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.13% (0.02128) | 79.47th | v5 (v2026.06.15) |
| Mar 17, 2025 | 1.43% (0.01427) | 79.29th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.14% (0.00136) | 50.64th | v3 (v2023.03.01) |
| Feb 2, 2024 | 0.14% (0.00136) | 48.99th | v3 (v2023.03.01) |
| Oct 20, 2023 | 0.19% (0.00192) | 56.79th | v3 (v2023.03.01) |
| Sep 10, 2023 | 0.23% (0.00233) | 60.79th | v3 (v2023.03.01) |
| Sep 3, 2023 | 0.36% (0.00355) | 68.47th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.40% (0.00395) | 69.26th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.21% (0.01213) | 66.61th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.21% (0.01213) | 40.54th | v2 (v2022.01.01) |
| Feb 3, 2022 | 1.31% (0.01306) | 31.19th | v5 (v2026.06.15) |
| Apr 14, 2021 | 1.31% (0.01306) | 0.00th | v1 |
References (4)
- http://www.securityfocus.com/bid/104018 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1040723 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://ics-cert.us-cert.gov/advisories/ICSA-18-184-01 x_refsource_MISCThird Party AdvisoryUS Government Resource
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-asa1 x_refsource_CONFIRMVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| http://www.securityfocus.com/bid/104018 | vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry | |
| http://www.securitytracker.com/id/1040723 | vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry | |
| https://ics-cert.us-cert.gov/advisories/ICSA-18-184-01 | x_refsource_MISCThird Party AdvisoryUS Government Resource | |
| https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-asa1 | x_refsource_CONFIRMVendor Advisory |
Change history (0)
No recorded changes yet.