CVE-2021-20279: Moodle/moodle Cross-Site Scripting Vulnerability
MODERATECVE-2021-20279 is a MODERATE (CVSS 5.4) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Moodle/moodle libraries in the Packagist ecosystem. The issue involves moodle contains stored xss via id number user profile field. Remediation is available by upgrading affected packages to version 3.10.2, 3.9.5, 3.8.8, 3.5.17.
CVE-2021-20279 at a Glance
Security Impact
CVSS: 5.4
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N).
How to Fix CVE-2021-20279
To remediate this vulnerability, upgrade all affected Moodle/moodle dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade moodle/moodle to 3.10.2Upgrade moodle/moodle to 3.9.5Upgrade moodle/moodle to 3.8.8Upgrade moodle/moodle to 3.5.17Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for moodle/moodleHow to Check if You Are Affected
To determine whether your application is affected by CVE-2021-20279, inspect your project dependencies for Moodle/moodle:
inspect dependencies for moodle/moodleAnalyze the terminal output to locate any version of Moodle/moodle in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.10.2), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Moodle/moodle, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2021-20279 Affected Moodle/moodle Versions
4 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
moodle/moodle
|
Packagist |
≥ 3.10
< 3.10.2
|
3.10.2
|
|
moodle/moodle
|
Packagist |
≥ 3.9
< 3.9.5
|
3.9.5
|
|
moodle/moodle
|
Packagist |
≥ 3.8
< 3.8.8
|
3.8.8
|
|
moodle/moodle
|
Packagist |
≥ 3.5
< 3.5.17
|
3.5.17
|
References
Frequently Asked Questions
What is CVE-2021-20279?
Which Moodle/moodle versions are affected?
What version fixes CVE-2021-20279?
Is moodle/moodle affected?
What is the CVSS score of CVE-2021-20279?
What CWE is associated with CVE-2021-20279?
How can I check Packagist dependencies for CVE-2021-20279?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-h7h6-fwpv-ggvx",
"modified" : "2023-07-13T17:04:27Z",
"published" : "2022-05-24T17:44:37Z",
"aliases" : [ "CVE-2021-20279" ],
"summary" : "Moodle contains Stored XSS via ID number user profile field",
"details" : "The ID number user profile field required additional sanitizing to prevent a stored XSS risk in moodle before 3.10.2, 3.9.5, 3.8.8, 3.5.17.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Packagist",
"name" : "moodle/moodle"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "3.10"
}, {
"fixed" : "3.10.2"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 3.10.1"
}
}, {
"package" : {
"ecosystem" : "Packagist",
"name" : "moodle/moodle"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "3.9"
}, {
"fixed" : "3.9.5"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 3.9.4"
}
}, {
"package" : {
"ecosystem" : "Packagist",
"name" : "moodle/moodle"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "3.8"
}, {
"fixed" : "3.8.8"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 3.8.7"
}
}, {
"package" : {
"ecosystem" : "Packagist",
"name" : "moodle/moodle"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "3.5"
}, {
"fixed" : "3.5.17"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 3.5.16"
}
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-20279"
}, {
"type" : "WEB",
"url" : "https://github.com/moodle/moodle/commit/a7e0ba1e71205ccb0a73dedee414f1a167ee2ed7"
}, {
"type" : "WEB",
"url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1939033"
}, {
"type" : "WEB",
"url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/AFSNJ7XHVTC52RSRX2GBQFF3VEEAY2MS"
}, {
"type" : "WEB",
"url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UFH5DDMU5TZ3JT4Q52WMRAHACA5MHIMT"
}, {
"type" : "WEB",
"url" : "https://moodle.org/mod/forum/discuss.php?d=419650"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-79" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2023-07-13T17:04:27Z",
"nvd_published_at" : "2021-03-15T22:15:00Z"
}
}