A certain pseudo-random number generator (PRNG) algorithm that uses XOR and 2-bit random hops (aka "Algorithm X2"), as used in OpenBSD 2.6 through 3.4, Mac OS X 10 through 10.5.1, FreeBSD 4.4 through 7.0, and DragonFlyBSD 1.0 through 1.10.1, allows remote attackers to guess sensitive values such as IP fragmentation IDs by observing a sequence of previously generated values. NOTE: this issue can be leveraged for attacks such as injection into TCP packets and OS fingerprinting.
Conclusion & alert: CVE-2008-1147 is rated Moderate Risk (56/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.61%). 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 | 2026-05-20 | 1.51% | 1.61% | +0.10% |
| 2 | 2026-03-30 | 1.33% | 1.51% | +0.18% |
| 3 | 2025-03-17 | — | 1.33% | — |
Full EPSS history (11 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.8 | 2.0 | MEDIUM |
|
8.6 | 6.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| cosmicperl | directory_pro | 10.0.3 | cpe:2.3:a:cosmicperl:directory_pro:10.0.3:*:*:*:*:*:*:* |
| darwin | darwin | 1.0 | cpe:2.3:a:darwin:darwin:1.0:*:*:*:*:*:*:* |
| darwin | darwin | 9.1 | cpe:2.3:a:darwin:darwin:9.1:*:*:*:*:*:*:* |
| navision | financials_server | 3.0 | cpe:2.3:a:navision:financials_server:3.0:*:*:*:*:*:*:* |