The NSEPA.NsepaCtrl.1 ActiveX control in nsepa.ocx in Citrix Access Gateway Enterprise Edition 8.1 before 8.1-67.7, 9.0 before 9.0-70.5, and 9.1 before 9.1-96.4 attempts to validate signed DLLs by checking the certificate subject, not the signature, which allows man-in-the-middle attackers to execute arbitrary code via HTTP header data referencing a DLL that was signed with a crafted certificate.
Conclusion & alert: CVE-2011-2883 is rated Moderate Risk (57.4/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.37%). 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 | 2025-08-25 | 0.48% | 0.37% | -0.11% |
| 2 | 2025-03-30 | 1.38% | 0.48% | -0.90% |
| 3 | 2025-03-29 | — | 1.38% | — |
Full EPSS history (7 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.3 | 2.0 | HIGH |
|
8.6 | 10.0 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| citrix | access_gateway | 8.1 | cpe:2.3:a:citrix:access_gateway:8.1:*:enterprise:*:*:*:*:* |
| citrix | access_gateway | 9.0 | cpe:2.3:a:citrix:access_gateway:9.0:*:enterprise:*:*:*:*:* |
| citrix | access_gateway | 9.1 | cpe:2.3:a:citrix:access_gateway:9.1:*:enterprise:*:*:*:*:* |