CVE-2011-5279

CVE-2011-5279 is a medium-severity vulnerability in Microsoft Internet Information Services with a CVSS 2.0 base score of 5.0. Its EPSS exploit-prediction score of 19% places it in the 97th percentile, indicating an elevated likelihood of exploitation.

Key facts

Description

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.

Frequently asked questions

What is CVE-2011-5279?
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.
How severe is CVE-2011-5279?
CVE-2011-5279 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2011-5279 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 19% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-5279?
CVE-2011-5279 primarily affects Microsoft Internet Information Services. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2011-5279?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2011-5279 published?
CVE-2011-5279 was published on 2014-04-23 and last updated on 2026-06-16.

References

Affected products (2)

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