The __VIEWSTATE functionality in Microsoft ASP.NET 1.x allows remote attackers to conduct replay attacks to (1) apply a ViewState generated from one view to a different view, (2) reuse ViewState information after the application's state has changed, or (3) use the ViewState to conduct attacks or expose content to third parties.
Conclusion & alert: CVE-2005-1664 is rated Moderate Risk (61.4/100): CVSS Medium severity, with high exploitation likelihood (EPSS 22.02%, 96th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +2.37% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize 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 | 2025-12-28 | 19.65% | 22.02% | +2.37% |
| 2 | 2025-12-27 | 22.02% | 19.65% | -2.37% |
| 3 | 2025-10-28 | — | 22.02% | — |
Full EPSS history (17 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.4 | 2.0 | MEDIUM |
|
10.0 | 4.9 | [email protected] |