Cisco Adaptive Security Appliance and Firepower Threat Defense Unauthorized Access Vulnerability
Cisco Adaptive Security Appliance and Firepower Threat Defense contain an unauthorized access vulnerability that could allow an unauthenticated, remote attacker to conduct a brute force attack in an attempt to identify valid username and password combinations or establish a clientless SSL VPN session with an unauthorized user.
- Vendor
- Cisco
- Product
- Adaptive Security Appliance and Firepower Threat Defense
- CVSS
- 5.0
- EPSS (exploit probability)
- 26.6%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2023-20269 being exploited?
Yes. CISA added CVE-2023-20269 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 26.6% (scored October 25, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-11-13. Full cross-catalog view: /kev-comparison
CVE-2023-20269 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
What to do
CISA required actionApply mitigations per vendor instructions for group-lock and vpn-simultaneous-logins or discontinue use of the product for unsupported devices.
US federal civilian agencies must remediate by (21 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-20349 Cisco ASA and FTD VPN Heap Inspection Denial-of-Service Flawwrite-up | [ HIGH ] | 8.6 | 1.0% | |
| CVE-2025-20362 Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Missing Authorization Vulnerability | [ MEDIUM ] | 6.5 | 86.7% | |
| CVE-2025-20333 Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability | [ CRITICAL ] | 9.9 | 72.0% | |
| CVE-2024-20481 Cisco ASA and FTD Denial-of-Service Vulnerability | [ MEDIUM ] | 5.8 | 15.9% | |
| CVE-2024-20359 Cisco ASA and FTD Privilege Escalation Vulnerability | [ MEDIUM ] | 6.0 | 18.8% | |
| CVE-2024-20353 Cisco ASA and FTD Denial of Service Vulnerability | [ HIGH ] | 8.6 | 69.8% | |
| CVE-2020-3259 Cisco ASA and FTD Information Disclosure Vulnerabilityransomware use | [ HIGH ] | 7.5 | 71.5% | |
| CVE-2020-3580 Cisco ASA and FTD Cross-Site Scripting (XSS) Vulnerabilityransomware use | [ MEDIUM ] | 6.1 | 85.6% |