CVE-2011-5279

Exp

CRLF injection vulnerability in the CGI implementation in Microsoft Internet Information Services (IIS) 4.x and 5.x on Windows NT and Windows 2000 allows remote attackers to modify arbitrary uppercase environment variables via a \n (newline) character in an HTTP header.

Published: 2014-04-23 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

NVD Status：Modified，CVE State: published

View at NVD, CVE.org, EUVD

Conclusion & alert: CVE-2011-5279 is rated High Exploit Risk (73.9/100): CVSS Medium severity, with high exploitation likelihood (EPSS 19.09%, 97th percentile). Core evidence: 5 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +11.06% over the last day, indicating growing attacker interest. 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.

Public exploit references (Exploit-DB) for CVE-2011-5279

EDB-ID	Source	Kind	Link
—	nvd_ref	exploit_tag	Exploit-DB ↗
—	nvd_ref	exploit_tag	Exploit-DB ↗
—	nvd_ref	exploit_tag	Exploit-DB ↗
—	nvd_ref	exploit_tag	Exploit-DB ↗
—	nvd_ref	exploit_tag	Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2011-5279

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	2026-06-15	8.03%	19.09%	+11.06%
2	2026-06-13	8.55%	8.03%	-0.52%
3	2025-12-28	—	8.55%	—

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2011-5279

CVSS metrics for this CVE.

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.0	2.0	MEDIUM	`AV:N/AC:L/Au:N/C:N/I:P/A:N` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:N) No availability impact.	10.0	2.9	[email protected]

Weakness enumeration for CVE-2011-5279

Affected software / configurations for CVE-2011-5279

Vendor	Product	Version	Raw CPE
microsoft	internet_information_services	4.0	cpe:2.3:a:microsoft:internet_information_services:4.0:::::::*
microsoft	internet_information_services	5.0	cpe:2.3:a:microsoft:internet_information_services:5.0:::::::*

References for CVE-2011-5279

URL	Tags
http://hi.baidu.com/yuange1975/item/b2cc7141c22108e91e19bc2e	Third Party Advisory
http://seclists.org/fulldisclosure/2012/Apr/0	Exploit Mailing List Third Party Advisory
http://seclists.org/fulldisclosure/2012/Apr/13	Exploit Mailing List Third Party Advisory
http://seclists.org/fulldisclosure/2014/Apr/108	Exploit Mailing List Third Party Advisory
http://seclists.org/fulldisclosure/2014/Apr/128	Exploit Mailing List Third Party Advisory
http://seclists.org/fulldisclosure/2014/Apr/247	Exploit Mailing List Third Party Advisory

cvelogic Threat Intelligence