Security readout for executives and security teams
Plain-English summary
This flaw affects older Magento Commerce storefronts and can let an unauthenticated attacker cause JavaScript to run in a user's browser through mage-messages cookie handling. User interaction is required. Business impact is mainly customer-session risk, data exposure in the browser, and possible trust damage for ecommerce sites.
Executive priority
Schedule remediation in the normal security patch cycle, faster for customer-facing stores handling sensitive account or checkout activity. This is not evidenced as actively exploited here, but ecommerce exposure and high confidentiality impact justify timely action.
Technical view
CVE-2021-28556 is a DOM-based XSS issue in Adobe Magento Commerce involving mage-messages cookies. Listed affected branches are 2.4.2 and earlier, 2.4.1-p1 and earlier, and 2.3.6-p1 and earlier. CVSS 3.1 is 6.9 with changed scope, high confidentiality impact, low integrity impact, and no availability impact.
Likely exposure
Exposure is most likely on public Magento Commerce storefronts running the listed older versions. The source bundle does not identify Magento Open Source, specific extensions, or downstream packaged products as affected, so do not broaden scope without vendor evidence.
Exploitation context
The source bundle says exploitation is unauthenticated but requires user interaction. It does not report active exploitation, and this CVE is not marked as CISA KEV in the provided data. Treat internet-facing ecommerce instances as higher priority because browser-side compromise can affect customers.
Researcher notes
Evidence is limited to the CVE record and Adobe advisory reference. The affected component is mage-messages cookie handling, but the bundle does not include fixed version details, proof-of-concept material, or exploit telemetry. Scope validation should stay tied to Magento Commerce versions named in the record.
Mitigation direction
- Inventory Magento Commerce versions across public and internal storefronts.
- Review Adobe APSB21-30 for the vendor-specified update or remediation path.
- Prioritize remediation for internet-facing stores on affected versions.
- Avoid inventing compensating controls; confirm vendor guidance first.
- Regression-test checkout, login, and message display flows after remediation.
Validation and detection
- Confirm whether each instance is Magento Commerce 2.4.2 or earlier.
- Check for 2.4.1-p1 or 2.3.6-p1 branch exposure.
- Verify remediation status against Adobe APSB21-30, not assumptions.
- Review frontend code paths that consume mage-messages cookies.
- Use safe XSS validation methods; do not test against live customers.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-28556 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N1.74.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.9MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://helpx.adobe.com/security/products/magento/apsb21-30.htmlCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.