FKIE_CVE-2026-89092

Vulnerability from fkie_nvd - Published: 2026-09-11 02:18 - Updated: 2026-10-26 23:10
Severity
4.2 (Medium) - CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
Summary
The nscd service in the GNU C Library 2.3.4 onwards may crash due to a stack overflow when a malicious DNS server returns too large a response for a DNS query, resulting in degraded DNS resolution for the system. Exploitation of this bug needs a system that has nscd enabled and using an untrusted DNS server for name resolution, with the compromised DNS server being capable of processing records large enough to result in a stack overflow in an nscd thread stack.  During experimentation, bind 9 was unable to handle large records, but that could change in future or with a different name server.  In typical installations, nscd is executed in an isolated context as its own user without a shell, due to which any compromise of that service is isolated. There is a remote possibility of nscd cache corruption if an attacker manages to get the stack pointer into a desired point in the heap, potentially resulting in other caches in nscd being overwritten with corrupt data through the stack overflow, until the buggy code path eventually results in a crash. Finally, a crash in nscd may result in performance degradation when resolving names, but it does not result in a denial of service.
References
3ff69d7a-14f2-4f67-a097-88dee7810d18https://sourceware.org/bugzilla/show_bug.cgi?id=34624
3ff69d7a-14f2-4f67-a097-88dee7810d18https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0016
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2026/09/11/2
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "glibc",
          "vendor": "The GNU C Library",
          "versions": [
            {
              "lessThan": "2.45",
              "status": "affected",
              "version": "2.3.4",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The nscd service in the GNU C Library 2.3.4 onwards may crash due to a \nstack overflow when a malicious DNS server returns too large a response \nfor a DNS query, resulting in degraded DNS resolution for the system.\n\n\n\nExploitation of this bug needs a system that has nscd enabled and using \nan untrusted DNS server for name resolution, with the compromised DNS \nserver being capable of processing records large enough to result in a \nstack overflow in an nscd thread stack.\u00a0 During experimentation, bind 9 \nwas unable to handle large records, but that could change in future or \nwith a different name server.\u00a0 In typical installations, nscd is \nexecuted in an isolated context as its own user without a shell, due to \nwhich any compromise of that service is isolated.\n\n\n\nThere is a remote possibility of nscd cache corruption if an attacker \nmanages to get the stack pointer into a desired point in the heap, \npotentially resulting in other caches in nscd being overwritten with \ncorrupt data through the stack overflow, until the buggy code path \neventually results in a crash.\n\n\n\nFinally, a crash in nscd may result in performance degradation when \nresolving names, but it does not result in a denial of service."
    },
    {
      "lang": "es",
      "value": "El servicio nscd en la Biblioteca C de GNU a partir de la versi\u00f3n 2.3.4 puede fallar debido a un desbordamiento de pila cuando un servidor DNS malicioso devuelve una respuesta demasiado grande para una consulta DNS, lo que provoca una degradaci\u00f3n de la resoluci\u00f3n DNS del sistema.\\n\\nExplotar este error requiere un sistema que tenga nscd habilitado y que utilice un servidor DNS no confiable para la resoluci\u00f3n de nombres, con el servidor DNS comprometido capaz de procesar registros lo suficientemente grandes como para generar un desbordamiento de pila en la pila de un hilo de nscd. Durante la experimentaci\u00f3n, bind 9 no pudo manejar registros grandes, pero eso podr\u00eda cambiar en el futuro o con un servidor de nombres diferente. En instalaciones t\u00edpicas, nscd se ejecuta en un contexto aislado como su propio usuario sin shell, por lo que cualquier compromiso de ese servicio queda aislado.\\n\\nExiste una posibilidad remota de corrupci\u00f3n de la cach\u00e9 de nscd si un atacante logra colocar el puntero de pila en un punto deseado del mont\u00edculo, lo que podr\u00eda resultar en que otras cach\u00e9s en nscd sean sobrescritas con datos corruptos mediante el desbordamiento de pila, hasta que la ruta de c\u00f3digo defectuosa finalmente provoque un fallo.\\n\\nFinalmente, un fallo en nscd puede provocar una degradaci\u00f3n del rendimiento al resolver nombres, pero no genera una denegaci\u00f3n de servicio."
    }
  ],
  "id": "CVE-2026-89092",
  "lastModified": "2026-10-26T23:10:00.183",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 4.2,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 2.5,
        "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-89092",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-11T16:57:22.665457Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-11T02:18:35.460",
  "references": [
    {
      "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
      "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34624"
    },
    {
      "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
      "url": "https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0016"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/11/2"
    }
  ],
  "sourceIdentifier": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-789"
        }
      ],
      "source": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
      "type": "Secondary"
    }
  ]
}



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