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    Zero-Day Research/CVE-2019-20443
    ▲ MediumCVSS 4.8✓ PatchedEPSS 0.00434%

    Stored Cross-Site Scripting in WSO2

    An issue was discovered in WSO2 API Manager 2.6.0, WSO2 Enterprise Integrator 6.5.0, WSO2 IS as Key Manager 5.7.0, and WSO2 Identity Server 5.8.0. A potential stored Cross-Site Scripting (XSS) vulnerability in mediaType has been identified in the registry UI.

    CVE IDCVE-2019-20443
    CVSS v3.14.8 Medium
    VendorWSO2
    CWECWE-79
    DisclosedJan 2, 2020
    StatusFixed
    All advisories
    • 01Description
    • 02Proof of Concept
    • 03Impact
    • 04Remediation
    • 05Timeline
    • 06References
    01/Description

    What this actually is.

    Technical background, root cause, and affected surface.

    This vulnerability was discovered on the WSO2 Identity Server before 5.7.0. A stored cross-site script (XSS) vulnerability allows an attacker to inject malicious code into the application and stored in the server. An input variable vulnerable to stored XSS is ‘mediaType’ on the browser page.

    *Affected Products: WSO2 API Manager, WSO2 API Manager Analytics, WSO2 Enterprise Integrator, WSO2 IS as Key Manager, WSO2 Identity Server, WSO2 Identity Server Analytics

    Vendor
    WSO2
    Affected Product
    See Full List Below*
    CVE
    CVE-2019-20443
    Securin ID
    2019-CSW-01-1024
    Status
    Fixed
    Date
    January 2, 2020
    Severity
    Medium
    CVSS Score
    4.8
    Vector
    CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
    CWE
    CWE-79
    02/Proof of Concept

    From one request
    to root shell.

    Reproduced in a sandboxed environment. Requires only LAN or WiFi adjacency.

    4.8CVSS 3.1
    VectorCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
    ScopeChanged
    ImpactC:L / I:L / A:N
    SeverityMedium

    The following vulnerability was tested on WSO2 Identity Server version 5.7.0 Product.

    PoC · Exploitation Steps▲ trigger
    01Issue 01: Stored Cross-Site Scripting.02Figure 01: Edit “Media Type” value in the “Metadata” section.03Figure 02: Save “Media Type” with XSS payload, “><img src=x onerror=prompt(1)>04Figure 03: Injected XSS payload gets stored to the application.05Figure 04: Injected XSS Payload gets stored and executed in the browser.06Figure 05: The stored XSS payload gets executed in four different places throughout the page whenever the user loads the page.
    03/Impact

    What an attacker does to you.

    Post-exploitation outcomes mapped to CVSS impact metrics.

    Through an XSS attack, the attacker can make the browser redirect to a malicious website. Unauthorized actions such as changing the UI of the web page, retrieving information from the browser are possible. But since all session-related sensitive cookies are set with httpOnly flat and protected, session hijacking or mounting a similar attack would not be possible.

    04/Remediation

    Fix it. In this order.

    A runbook, not a checklist. Sequence matters — assume compromise before you act.

    Download the following relevant patch based on your product version.

    Securin advisory — For coordinated remediation support or threat-actor briefings related to CVE-2019-20443, contact disclose@securin.io
    05/Disclosure Timeline

    Vendors moved in days.
    Attackers in hours.

    Reconstructed from vendor advisories, CISA bulletins, and Securin research records.

    Jul 02, 2019

    Discovered CVE-2019-20443 in WS02 Identity Server 5.7.0 Version.

    Jul 02, 2019

    Report sent to WS02.

    Jul 02, 2019

    WS02 acknowledged the report.

    Aug 13, 2019

    Fixing was initiated in all affected versions.

    Sep 10, 2019

    The vendor informed their customers about the vulnerability.

    Oct 10, 2019

    Public announcement by the vendor about the vulnerability.

    Timeline recorded · Disclosure coordinated by Securin

    06/References

    Cite, verify, go deeper.

    Primary sources — NVD, CISA KEV, and machine-readable IoC feed.

    NVD

    NVD — CVE-2019-20443

    nvd.nist.gov/vuln/detail/CVE-2019-20443 →
    SEC

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