CVE-2011-4203: n/a vulnerability

CVE-2011-4203: CRLF injection vulnerability in calendar/set.php in the Calendar component in Moodle 1.9.x before 1.9.15, 2...

CRLF injection vulnerability in calendar/set.php in the Calendar component in Moodle 1.9.x before 1.9.15, 2.0.x before 2.0.6, 2.1.x before 2.1.3, and 2.2 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via vectors involving the url variable.

UnknownCVSS not scoredNot KEV-listedUpdatedSep 17, 2024, 02:15 UTC (UTC+00:00)

Security readout for executives and security teams

This CVE affects older Moodle Calendar code. A remote attacker could manipulate the url parameter so the application emits attacker-controlled HTTP headers, enabling HTTP response splitting. Business urgency depends on whether any public or legacy Moodle instances still run the affected versions. Exposure is most likely in legacy Moodle deployments, especially internet-facing learning platforms still running the named 1.9.x, 2.0.x, 2.1.x, or 2.2 versions. Treat this as a legacy-platform risk. Prioritize if Moodle is internet-facing, handles authenticated learning sessions, or sits behind shared proxies or caches. Mitigation focus: Inventory Moodle instances and identify exact versions in production and staging.; Upgrade Moodle 1.9.x to 1.9.15 or later where applicable.; Upgrade Moodle 2.0.x to 2.0.6 or later where applicable..

Prepared: Jun 27, 2026, 17:28 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

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Vulnerability profileCVE Program record

Severity: Unknown
CVSS: Not scored
Known Exploited: No
Published: Dec 22, 2011, 15:00 UTC (UTC+00:00)

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

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1Source links

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Source materials

CVE List V5 sourceCVE List V5

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus

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Weakness

CWE details

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