Format string vulnerability in the h_readrequest function in http.c in httpdx Web Server 1.4 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via format string specifiers in the Host header.
Conclusion & alert: CVE-2009-3663 is rated High Exploit Risk (87.8/100): CVSS Critical severity, with high exploitation likelihood (EPSS 17.16%, 95th percentile). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| 9657 | exploit_db | edb | 2009-09-14 | Exploit-DB ↗ |
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 | 2026-04-29 | 17.66% | 17.16% | -0.50% |
| 2 | 2026-03-02 | 19.33% | 17.66% | -1.67% |
| 3 | 2025-03-30 | — | 19.33% | — |
Full EPSS history (9 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 10.0 | 2.0 | HIGH |
|
10.0 | 10.0 | [email protected] |