Security readout for executives and security teams
Plain-English summary
MStore API trusts Firebase phone-login tokens without proving they were signed by Google. An unauthenticated attacker could therefore impersonate a phone number, access an existing WordPress account, or create an arbitrary account. Because exploitation requires no credentials or user interaction and could compromise site data and administration, the supplied CVSS 3.1 rating is 9.8.
Executive priority
Treat this as an immediate remediation priority on internet-facing or business-critical WordPress sites. Inventory affected installations, reduce access to the vulnerable authentication path, investigate suspicious account activity, and obtain the vendor-confirmed corrected version. Potential account takeover makes delay materially risky even though active exploitation is not established by the supplied sources.
Technical view
In versions reported through 4.20.0, FirebasePhoneAuthHelper::verify_id_token() checks JWT claims such as alg, kid, aud, and iss but does not cryptographically verify the signature against Google certificates. Consequently, attacker-created tokens may be accepted by Firebase phone-authentication flows, producing a CWE-287 authentication bypass.
Likely exposure
Potentially exposed sites run MStore API 4.20.0 or earlier and make its Firebase phone-authentication functionality reachable. Risk is greatest when phone identities map to privileged existing accounts or allow account registration. The bundle’s structured affected-version field is inconsistent with its title and description, so administrators should confirm the exact range with vendor guidance.
Exploitation context
The flaw is remotely reachable, requires no authentication or victim interaction, and is rated low complexity. The supplied bundle does not identify CISA KEV listing or provide evidence of active exploitation. That absence should not be interpreted as proof that exploitation has not occurred.
Researcher notes
The evidence describes a trust failure, not merely weak claim validation: attacker-controlled signatures are never verified. However, the bundle lists an anomalous affected value of “0” with default status “unaffected,” while its narrative says through 4.20.0. No fixed version, vendor mitigation, or exploitation telemetry is supplied; validate those points independently before asserting remediation completeness.
Mitigation direction
- Identify sites running MStore API and record their installed versions.
- Check current vendor guidance for a corrected release and apply it when confirmed.
- Until corrected, disable the plugin or Firebase phone authentication where operationally acceptable.
- Restrict unnecessary access to affected authentication interfaces as a temporary risk-reduction measure.
- Review newly created and unexpectedly accessed WordPress accounts for possible compromise.
Validation and detection
- Confirm whether MStore API 4.20.0 or earlier is installed on each WordPress site.
- Determine whether Firebase phone authentication is enabled and externally reachable.
- Verify the deployed implementation cryptographically validates token signatures using trusted Google keys.
- Check authentication and account-creation records for unexplained phone identities or privilege changes.
- Confirm the vendor-designated fixed version before closing remediation work.
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-287: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. 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 lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-13447 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
SSVC decision data
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:N/UI:N/S:U/C:H/I:H/A:H3.95.9WordfenceVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- Source timelineWordfence
Vendor Notified
- Source timelineWordfence
Disclosed
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/4a1127af-74f6-4748-9aee-5a8c6c2766a4?source=cveCVE reference, Wordfence
- https://plugins.trac.wordpress.org/browser/mstore-api/trunk/controllers/helpers/firebase-phone-auth-helper.php#L5CVE reference, Wordfence
- https://plugins.trac.wordpress.org/browser/mstore-api/trunk/controllers/flutter-user.php#L940CVE reference, Wordfence
- https://plugins.trac.wordpress.org/browser/mstore-api/tags/4.18.4/controllers/helpers/firebase-phone-auth-helper.php#L5CVE reference, Wordfence
- https://plugins.trac.wordpress.org/browser/mstore-api/tags/4.18.4/controllers/flutter-user.php#L940CVE reference, Wordfence
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.
Improper Authentication
Improper Authentication represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.