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CVE-2020-0421

Status: ModifiedHigh (7.8)—💥 PoC

In appendFormatV of String8.cpp, there is a possible out of bounds write due to incorrect error handling. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-8.1 Android-9 Android-10 Android-11 Android-8.0Android ID: A-161894517

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

💥 Public exploits

Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.

⚠️ GitHub proofs of concept are not verified: some are fake or contain malware. Never run them outside an isolated lab.

Affected technologies (1)

Google — Android

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2020-0421",
  "cveTags": [],
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        "source": "nvd@nist.gov",
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          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:L/Au:N/C:C/I:C/A:C",
          "authentication": "NONE",
          "integrityImpact": "COMPLETE",
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        "acInsufInfo": false,
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  "published": "2020-10-14T14:15:17.170",
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  "vulnStatus": "Modified",
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      "description": [
        {
          "lang": "en",
          "value": "CWE-755"
        },
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In appendFormatV of String8.cpp, there is a possible out of bounds write due to incorrect error handling. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-8.1 Android-9 Android-10 Android-11 Android-8.0Android ID: A-161894517"
    },
    {
      "lang": "es",
      "value": "En la función appendFormatV del archivo String8.cpp, se presenta una posible escritura fuera de límites debido a un manejo incorrecto de errores. Esto podría conllevar a una escalada de privilegios local sin ser necesarios privilegios de ejecución adicionales. No es requerida una interacción del usuario para su explotación. Producto: Android, Versiones: Android-8.1 Android-9 Android-10 Android-11 Android-8.0, ID de Android: A-161894517"
    }
  ],
  "lastModified": "2026-06-17T02:45:48.723",
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