CVE-2011-2882
CriticalPublic exploitStack-based buffer overflow in 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 allows remote attackers to execute arbitrary code via crafted HTTP header data.
Published Jul 21, 2011 · Updated Apr 28, 2026
Key Facts
Patch immediately- CVE-2011-2882 is a critical-severity vulnerability (CVSS 9.3 v2) affecting Access Gateway (Citrix).
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 56% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v2
9.3
AV:N/AC:M/Au:N/C:C/I:C/A:C
EPSS (30-day exploit likelihood)
56%
Higher than 99.0% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2011-2882 brief as a PDF
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Description
Stack-based buffer overflow in 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 allows remote attackers to execute arbitrary code via crafted HTTP header data.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Access GatewayCitrix | 8.1, 9.0, 9.1 | n/a |
Timeline
Publicly disclosed
Jul 21, 2011
Last updated
Apr 28, 2026
Weakness Type
- CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
References
FAQ
Common Questions.
Stack-based buffer overflow in 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 allows remote attackers to execute arbitrary code via crafted HTTP header data.
Affected: Access Gateway (Citrix) versions 8.1, 9.0, 9.1. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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