CVE-2021-21043: Acs aem commons Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-7r83-w6r8-fh6w
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CVSS 6.1
CWE-787 CWE-79
Published
Advisory Summary

CVE-2021-21043 is a MODERATE (CVSS 6.1) cross-site scripting vulnerability (CWE-787: Out-of-bounds Write) affecting Acs aem commons libraries in the Maven ecosystem. The issue involves reflected cross-site scripting (xss) in acs commons. Remediation is available by upgrading affected packages to version 4.10.0.

CVE-2021-21043 at a Glance

CVE Identifier CVE-2021-21043
GHSA Identifier GHSA-7r83-w6r8-fh6w
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-787: Out-of-bounds Write
Affected Product Acs aem commons
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 6.1

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:R/S:C/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
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-2021-21043

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

com.adobe.acs:acs-aem-commons fixed: 4.10.0 
<dependency>
    <groupId>com.adobe.acs</groupId>
    <artifactId>acs-aem-commons</artifactId>
    <version>4.10.0</version>
</dependency>
Verify Direct and Transitive Dependencies

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

mvn dependency:tree -Dincludes=com.adobe.acs

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-21043, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=com.adobe.acs

Analyze the terminal output to locate any version of Acs aem commons in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.10.0), your application is affected.

Note: The mvn dependency:tree -Dincludes=com.adobe.acs command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-787: Out-of-bounds Write, where the product writes data past the end, or before the beginning, of the intended buffer. In Acs aem commons, 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

ACS Commons version 4.9.2 (and earlier) suffers from a Reflected Cross-site Scripting (XSS) vulnerability in version-compare and page-compare due to invalid JCR characters that are not handled correctly. An attacker could potentially exploit this vulnerability to inject malicious JavaScript content into vulnerable form fields and execute it within the context of the victim's browser. Exploitation of this issue requires user interaction in order to be successful.

CVE-2021-21043 Affected Acs aem commons Versions

1 component(s)
Fixed Versions:
4.10.0
Product / Package Ecosystem Affected Versions Fixed Version
com.adobe.acs:acs-aem-commons
maven/com.adobe.acs/acs-aem-commons
Maven
< 4.10.0
4.10.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/Adobe-Consulting-Services/acs-aem-commons/security/advisories/GHSA-f92j-qf46-p6vm
NVD — CVE-2021-21043 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-21043
Security Fix Commit FIX COMMIT
https://github.com/Adobe-Consulting-Services/acs-aem-commons/commit/14d769c86606c4ce9a93c47a19f87e1ad72788d6
Acs aem commons Source Repository REPOSITORY
https://github.com/Adobe-Consulting-Services/acs-aem-commons
Acs aem commons Security Information SECURITY
https://helpx.adobe.com/security/products/indesign/apsb21-22.html

Frequently Asked Questions

What is CVE-2021-21043?
CVE-2021-21043 is a security vulnerability in Acs aem commons involving Reflected Cross-site Scripting (XSS) in ACS Commons under CWE-787: Out-of-bounds Write.
Which Acs aem commons versions are affected?
Affected versions include releases prior to 4.10.0 across affected packages: com.adobe.acs:acs-aem-commons.
What version fixes CVE-2021-21043?
Upgrading to 4.10.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is acs-aem-commons affected?
Yes, com.adobe.acs:acs-aem-commons is affected in releases prior to 4.10.0. Upgrade your dependency to 4.10.0 or later.
What is the CVSS score of CVE-2021-21043?
CVE-2021-21043 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2021-21043?
CVE-2021-21043 is classified under CWE-787: Out-of-bounds Write (The product writes data past the end, or before the beginning, of the intended buffer.).
How can I check Maven dependencies for CVE-2021-21043?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=com.adobe.acs'. 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-7r83-w6r8-fh6w",
  "modified" : "2021-12-13T21:34:08Z",
  "published" : "2021-05-13T22:31:14Z",
  "aliases" : [ "CVE-2021-21043" ],
  "summary" : "Reflected Cross-site Scripting (XSS) in ACS Commons",
  "details" : "ACS Commons version 4.9.2 (and earlier) suffers from a Reflected Cross-site Scripting (XSS) vulnerability in version-compare and page-compare due to invalid JCR characters that are not handled correctly. An attacker could potentially exploit this vulnerability to inject malicious JavaScript content into vulnerable form fields and execute it within the context of the victim's browser. Exploitation of this issue requires user interaction in order to be successful.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "com.adobe.acs:acs-aem-commons"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.10.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Adobe-Consulting-Services/acs-aem-commons/security/advisories/GHSA-f92j-qf46-p6vm"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-21043"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Adobe-Consulting-Services/acs-aem-commons/commit/14d769c86606c4ce9a93c47a19f87e1ad72788d6"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Adobe-Consulting-Services/acs-aem-commons"
  }, {
    "type" : "WEB",
    "url" : "https://helpx.adobe.com/security/products/indesign/apsb21-22.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-787", "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-04-05T21:38:56Z",
    "nvd_published_at" : "2021-02-02T23:15:00Z"
  }
}