UpHeron
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Servers and applications

CVE-2011-4203

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.

Severity
Medium 5.0
Published
22 Dec 2011
Last changed
16 Jun 2026
Added to UpHeron
1 Nov 2026
Exploit chance
1.2% in the next 30 daysHigher than 68% of CVEs. EPSS by FIRST, 12 Nov 2026
Weakness
Code injection (CWE-94)
Attack
Over the network · No login needed
Attacker can
Change some data
CVSS vector
AV:N/AC:L/Au:N/C:N/I:P/A:N
Sources
NVD

Affected software

SoftwareAffected versions
MoodleServers and applications · cpe:a:moodle:moodle
  • Version 2.2.0
  • Version 2.1.2
  • Version 2.1.1
  • Version 2.1.0
All 24 release lines
  • Version 1.9.1
  • Version 1.9.2
  • Version 1.9.3
  • Version 1.9.4
  • Version 1.9.5
  • Version 1.9.6
  • Version 1.9.7
  • Version 1.9.8
  • Version 1.9.9
  • Version 1.9.10
  • Version 1.9.11
  • Version 1.9.12
  • Version 1.9.13
  • Version 1.9.14
  • Version 2.0.0
  • Version 2.0.1
  • Version 2.0.2
  • Version 2.0.3
  • Version 2.0.4
  • Version 2.0.5
  • Version 2.1.0
  • Version 2.1.1
  • Version 2.1.2
  • Version 2.2.0

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2011-4203
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2011-4203