A vulnerability in the deterministic random bit generator (DRBG), also known as pseudorandom number generator (PRNG), in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software for Cisco ASA 5506-X, ASA 5508-X, and ASA 5516-X Firewalls could allow an unauthenticated, remote attacker to cause a cryptographic collision, enabling the attacker to discover the private key of an affected device. This vulnerability is due to insufficient entropy in the DRBG for the affected hardware platforms when generating cryptographic keys. An attacker could exploit this vulnerability by generating a large number of cryptographic keys on an affected device and looking for collisions with target devices. A successful exploit could allow the attacker to impersonate an affected target device or to decrypt traffic secured by an affected key that is sent to or from an affected target device.
Conclusion & alert: CVE-2023-20107 is rated Moderate Risk (59.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.61%). Core evidence: EPSS rose +1.12% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-13 | 0.50% | 1.61% | +1.12% |
| 2 | 2026-05-19 | 0.36% | 0.50% | +0.13% |
| 3 | 2026-03-24 | — | 0.36% | — |
Full EPSS history (12 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| 5.3 | 3.0 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| cisco | adaptive_security_appliance | < 9.12.1 | cpe:2.3:a:cisco:adaptive_security_appliance:*:*:*:*:*:*:*:* |
| cisco | firepower_threat_defense | < 6.4.0 | cpe:2.3:a:cisco:firepower_threat_defense:*:*:*:*:*:*:*:* |