CVE-2023-23923: Moodle/moodle Moodle Improper Access Control Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-32jc-9p58-p82x
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CVSS 8.2
CWE-284
Published
Advisory Summary

CVE-2023-23923 is a HIGH (CVSS 8.2) moodle improper access control vulnerability vulnerability (CWE-284: Improper Access Control) affecting Moodle/moodle libraries in the Packagist ecosystem. The issue involves moodle improper access control vulnerability. Remediation is available by upgrading affected packages to version 3.9.19, 3.11.12, 4.0.6, 4.1.1.

CVE-2023-23923 at a Glance

CVE Identifier CVE-2023-23923
GHSA Identifier GHSA-32jc-9p58-p82x
Severity HIGH
CVSS v3.1 Base Score 8.2
CWE Classification CWE-284: Improper Access Control
Affected Product Moodle/moodle
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 8.2

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2023-23923

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.

moodle/moodle fixed: 3.9.19 
Upgrade moodle/moodle to 3.9.19
moodle/moodle fixed: 3.11.12 
Upgrade moodle/moodle to 3.11.12
moodle/moodle fixed: 4.0.6 
Upgrade moodle/moodle to 4.0.6
moodle/moodle fixed: 4.1.1 
Upgrade moodle/moodle to 4.1.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for moodle/moodle

How to Check if You Are Affected

To determine whether your application is affected by CVE-2023-23923, inspect your project dependencies for Moodle/moodle:

inspect dependencies for moodle/moodle

Analyze 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 3.9.19), 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-284: Improper Access Control, where the product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. 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

The vulnerability was found Moodle which exists due to insufficient limitations on the "start page" preference. A remote attacker can set that preference for another user. The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

CVE-2023-23923 Affected Moodle/moodle Versions

4 component(s)
Fixed Versions:
3.9.193.11.124.0.64.1.1
Product / Package Ecosystem Affected Versions Fixed Version
moodle/moodle
 Packagist
< 3.9.19
3.9.19
moodle/moodle
 Packagist
≥ 3.10.0
< 3.11.12
3.11.12
moodle/moodle
 Packagist
≥ 4.0.0-beta
< 4.0.6
4.0.6
moodle/moodle
 Packagist
≥ 4.1.0-beta
< 4.1.1
4.1.1

References

NVD — CVE-2023-23923 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-23923
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2162549
Moodle/moodle Source Repository REPOSITORY
https://github.com/moodle/moodle
moodle.org/mod/forum/discuss.p... WEB
https://moodle.org/mod/forum/discuss.php?d=443274#p1782023
git.moodle.org/gw WEB
http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-76862

Frequently Asked Questions

What is CVE-2023-23923?
CVE-2023-23923 is a security vulnerability in Moodle/moodle involving Moodle Improper Access Control vulnerability under CWE-284: Improper Access Control.
Which Moodle/moodle versions are affected?
Affected versions include releases prior to 3.9.19, 3.11.12, 4.0.6, 4.1.1 across affected packages: moodle/moodle.
What version fixes CVE-2023-23923?
Upgrading to 3.9.19, 3.11.12, 4.0.6, 4.1.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is moodle/moodle affected?
Yes, moodle/moodle is affected in releases prior to 3.9.19, 3.11.12, 4.0.6, 4.1.1. Upgrade your dependency to 3.9.19, 3.11.12, 4.0.6, 4.1.1 or later.
What is the CVSS score of CVE-2023-23923?
CVE-2023-23923 has a CVSS v3.1 base score of 8.2 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.
What CWE is associated with CVE-2023-23923?
CVE-2023-23923 is classified under CWE-284: Improper Access Control (The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.).
How can I check Packagist dependencies for CVE-2023-23923?
Run the dependency tree command: 'inspect dependencies for moodle/moodle'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-32jc-9p58-p82x",
  "modified" : "2023-03-02T18:16:20Z",
  "published" : "2023-02-17T21:30:41Z",
  "aliases" : [ "CVE-2023-23923" ],
  "summary" : "Moodle Improper Access Control vulnerability",
  "details" : "The vulnerability was found Moodle which exists due to insufficient limitations on the \"start page\" preference. A remote attacker can set that preference for another user. The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "moodle/moodle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.9.19"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "moodle/moodle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.10.0"
      }, {
        "fixed" : "3.11.12"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "moodle/moodle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0-beta"
      }, {
        "fixed" : "4.0.6"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "moodle/moodle"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.1.0-beta"
      }, {
        "fixed" : "4.1.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-23923"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2162549"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/moodle/moodle"
  }, {
    "type" : "WEB",
    "url" : "https://moodle.org/mod/forum/discuss.php?d=443274#p1782023"
  }, {
    "type" : "WEB",
    "url" : "http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-76862"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-284" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-03-02T18:16:20Z",
    "nvd_published_at" : "2023-02-17T20:15:00Z"
  }
}