How severe is CVE-2013-4940?

CVE-2013-4940 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2013-4940 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2013-4940?

CVE-2013-4940 primarily affects Moodle. In total, 58 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2013-4940?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2013-4940 published?

CVE-2013-4940 was published on 2013-07-29 and last updated on 2026-06-16.

CVE-2013-4940

CVE-2013-4940 is a medium-severity vulnerability in Moodle with a CVSS 2.0 base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Moodle
Published: 2013-07-29
Last modified: 2026-06-16

Description

Cross-site scripting (XSS) vulnerability in io.swf in the IO Utility component in Yahoo! YUI 3.10.2, as used in Moodle through 2.1.10, 2.2.x before 2.2.11, 2.3.x before 2.3.8, 2.4.x before 2.4.5, 2.5.x before 2.5.1, and other products, allows remote attackers to inject arbitrary web script or HTML via a crafted string in a URL. NOTE: this vulnerability exists because of a CVE-2013-4939 regression.

Frequently asked questions

What is CVE-2013-4940?: Cross-site scripting (XSS) vulnerability in io.swf in the IO Utility component in Yahoo! YUI 3.10.2, as used in Moodle through 2.1.10, 2.2.x before 2.2.11, 2.3.x before 2.3.8, 2.4.x before 2.4.5, 2.5.x before 2.5.1, and other products, allows remote attackers to inject arbitrary web script or HTML via a crafted string in a URL. NOTE: this vulnerability exists because of a CVE-2013-4939 regression.
How severe is CVE-2013-4940?: CVE-2013-4940 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2013-4940 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2013-4940?: CVE-2013-4940 primarily affects Moodle. In total, 58 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2013-4940?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2013-4940 published?: CVE-2013-4940 was published on 2013-07-29 and last updated on 2026-06-16.

References

Affected products (58)

cpe:2.3:a:moodle:moodle:2.1.0:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.1.1:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.1.2:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.1.3:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.1.4:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.1.5:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.1.6:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.1.7:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.1.8:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.1.9:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.1.10:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.0:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.1:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.2:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.3:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.4:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.5:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.6:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.7:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.8:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.9:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.2.10:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.3.0:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.3.1:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.3.2:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.3.3:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.3.4:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.3.5:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.3.6:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.3.7:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.4.0:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.4.1:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.4.2:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.4.3:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.4.4:*:*:*:*:*:*:*
cpe:2.3:a:moodle:moodle:2.5.0:*:*:*:*:*:*:*
cpe:2.3:a:yahoo:yui:3.0.0:*:*:*:*:*:*:*
cpe:2.3:a:yahoo:yui:3.1.0:*:*:*:*:*:*:*
cpe:2.3:a:yahoo:yui:3.1.1:*:*:*:*:*:*:*
cpe:2.3:a:yahoo:yui:3.1.2:*:*:*:*:*:*:*

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