CVE-2021-20683: Baserproject/basercms Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-v9w8-hq92-v39m
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CVSS 5.4
CWE-79
Published
Advisory Summary

CVE-2021-20683 is a MODERATE (CVSS 5.4) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Baserproject/basercms libraries in the Packagist ecosystem. The issue involves cross-site scripting (xss) in basercms. Remediation is available by upgrading affected packages to version 4.4.5.

CVE-2021-20683 at a Glance

CVE Identifier CVE-2021-20683
GHSA Identifier GHSA-v9w8-hq92-v39m
Severity MODERATE
CVSS v3.1 Base Score 5.4
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Baserproject/basercms
Package Ecosystem Packagist
Published Date
Last Updated

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).

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

How to Fix CVE-2021-20683

To remediate this vulnerability, upgrade all affected Baserproject/basercms dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

baserproject/basercms fixed: 4.4.5 
Upgrade baserproject/basercms to 4.4.5
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 baserproject/basercms

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-20683, inspect your project dependencies for Baserproject/basercms:

inspect dependencies for baserproject/basercms

Analyze the terminal output to locate any version of Baserproject/basercms in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.4.5), 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 Baserproject/basercms, 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

Improper neutralization of JavaScript input in the blog article editing function of baserCMS versions prior to 4.4.5 allows remote authenticated attackers to inject an arbitrary script via unspecified vectors.

CVE-2021-20683 Affected Baserproject/basercms Versions

1 component(s)
Fixed Versions:
4.4.5
Product / Package Ecosystem Affected Versions Fixed Version
baserproject/basercms
 Packagist
< 4.4.5
4.4.5

References

NVD — CVE-2021-20683 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-20683
Security Fix Commit FIX COMMIT
https://github.com/baserproject/basercms/commit/88ccc61e5656b05dd13204d61de706efaa2cd0b1
Baserproject/basercms Security Information SECURITY
https://basercms.net/security/JVN64869876
jvn.jp/en/jp/jvn64869876/i... WEB
https://jvn.jp/en/jp/JVN64869876/index.html

Frequently Asked Questions

What is CVE-2021-20683?
CVE-2021-20683 is a security vulnerability in Baserproject/basercms involving Cross-site Scripting (XSS) in baserCMS under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Baserproject/basercms versions are affected?
Affected versions include releases prior to 4.4.5 across affected packages: baserproject/basercms.
What version fixes CVE-2021-20683?
Upgrading to 4.4.5 (or the latest patched release for your respective branch) resolves the vulnerability.
Is baserproject/basercms affected?
Yes, baserproject/basercms is affected in releases prior to 4.4.5. Upgrade your dependency to 4.4.5 or later.
What is the CVSS score of CVE-2021-20683?
CVE-2021-20683 has a CVSS v3.1 base score of 5.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2021-20683?
CVE-2021-20683 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (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.).
How can I check Packagist dependencies for CVE-2021-20683?
Run the dependency tree command: 'inspect dependencies for baserproject/basercms'. 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-v9w8-hq92-v39m",
  "modified" : "2021-03-29T22:34:30Z",
  "published" : "2021-06-08T20:10:45Z",
  "aliases" : [ "CVE-2021-20683" ],
  "summary" : "Cross-site Scripting (XSS) in baserCMS",
  "details" : "Improper neutralization of JavaScript input in the blog article editing function of baserCMS versions prior to 4.4.5 allows remote authenticated attackers to inject an arbitrary script via unspecified vectors.",
  "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" : "baserproject/basercms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.4.5"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-20683"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/baserproject/basercms/commit/88ccc61e5656b05dd13204d61de706efaa2cd0b1"
  }, {
    "type" : "WEB",
    "url" : "https://basercms.net/security/JVN64869876"
  }, {
    "type" : "WEB",
    "url" : "https://jvn.jp/en/jp/JVN64869876/index.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-03-29T22:34:30Z",
    "nvd_published_at" : "2021-03-26T09:15:00Z"
  }
}