« Volver al listado

CVE-2026-102720

Estado: Pendiente de análisisMedia (5.3)—

A DHCP server, or anyone on the LAN who answers a DISCOVER first, can make the client read about a

kilobyte past the end of the received message.

The option walk keeps a pointer and an offset in step, and the only bound check uses the offset:

```c

/* addons/dhcp/nxd_dhcp_client.c:7538, 7572 */

while (i < length - 1)

```

A TLV option occupies size + 2 bytes. `data` is advanced by size + 2 in total, `i` by size + 1, so

the offset falls one byte behind the real read position for every option the walk skips. After

enough skipped options the check `i < length - 1` still holds while `data` is already past the end

Leer descripción completaMostrar menos

of the message, and the subsequent read of the type and length bytes comes from whatever follows.

A single OFFER carrying a long run of skippable options is enough:

```

ERROR: AddressSanitizer: heap-buffer-overflow

0x61b000000794 is located 164 bytes to the right of 1648-byte region

```

A well formed OFFER through the same path is handled normally, the client records the offer and

moves to REQUESTING, so the difference is the option layout rather than the harness.

The read runs in the DHCP client thread while the client is still unconfigured, so it happens on

every boot in reach of a hostile DHCP responder. The values read are used to configure the

interface, which is how the disclosed bytes become observable.

Advance `i` by size + 2, or derive the bound from `data` rather than keeping a second counter.

Detalles técnicos trazas, registros y código del informe original
{

    ...
    size = *(++data);      /* data moves 1: type -> length byte */
    data += size + 1;      /* data moves size + 1 more          */
    i += size + 1;         /* i moves only size + 1             */

}

READ of size 1 at 0x61b000000794 thread T5

    #0 _nx_dhcp_search_buffer     addons/dhcp/nxd_dhcp_client.c:7541
    #1 _nx_dhcp_get_option_value  addons/dhcp/nxd_dhcp_client.c:7082

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Buffer overflow en cliente DHCP (CWE-125) tras DISCOVER/OFFER malicioso en LAN adyacente sin autenticación. Lectura de memoria fuera de límites en thread DHCP no configurado durante arranque; datos leídos observable al configurar interfaz.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-102720",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-102720",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-29T18:36:33.534376Z"
        }
      }
    ],
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "emo@eclipse.org",
        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
          "baseScore": 5.3,
          "Automatable": "NOT_DEFINED",
          "attackVector": "ADJACENT",
          "baseSeverity": "MEDIUM",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "vulnAvailabilityImpact": "LOW",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "confidentialityRequirement": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
        }
      }
    ]
  },
  "affected": [
    {
      "source": "emo@eclipse.org",
      "affectedData": [
        {
          "vendor": "Eclipse Foundation",
          "product": "eclipse-threadx/netxduo",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "versionType": "semver",
              "lessThanOrEqual": "6.5.1"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-09-29T18:17:11.377",
  "references": [
    {
      "url": "https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-8hj5-p46x-5h28",
      "source": "emo@eclipse.org"
    }
  ],
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "emo@eclipse.org",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A DHCP server, or anyone on the LAN who answers a DISCOVER first, can make the client read about a\n\n\n\nkilobyte past the end of the received message.\n\n\n\nThe option walk keeps a pointer and an offset in step, and the only bound check uses the offset:\n\n\n\n```c\n\n\n\n/* addons/dhcp/nxd_dhcp_client.c:7538, 7572 */\n\n\n\nwhile (i < length - 1)\n\n\n\n{\n\n    ...\n    size = *(++data);      /* data moves 1: type -> length byte */\n    data += size + 1;      /* data moves size + 1 more          */\n    i += size + 1;         /* i moves only size + 1             */\n\n\n}\n\n\n\n```\n\n\n\nA TLV option occupies size + 2 bytes. `data` is advanced by size + 2 in total, `i` by size + 1, so\n\n\n\nthe offset falls one byte behind the real read position for every option the walk skips. After\n\n\n\nenough skipped options the check `i < length - 1` still holds while `data` is already past the end\n\n\n\nof the message, and the subsequent read of the type and length bytes comes from whatever follows.\n\n\n\nA single OFFER carrying a long run of skippable options is enough:\n\n\n\n```\n\n\n\nERROR: AddressSanitizer: heap-buffer-overflow\n\n\n\nREAD of size 1 at 0x61b000000794 thread T5\n\n    #0 _nx_dhcp_search_buffer     addons/dhcp/nxd_dhcp_client.c:7541\n    #1 _nx_dhcp_get_option_value  addons/dhcp/nxd_dhcp_client.c:7082\n\n\n0x61b000000794 is located 164 bytes to the right of 1648-byte region\n\n\n\n```\n\n\n\nA well formed OFFER through the same path is handled normally, the client records the offer and\n\n\n\nmoves to REQUESTING, so the difference is the option layout rather than the harness.\n\n\n\nThe read runs in the DHCP client thread while the client is still unconfigured, so it happens on\n\n\n\nevery boot in reach of a hostile DHCP responder. The values read are used to configure the\n\n\n\ninterface, which is how the disclosed bytes become observable.\n\n\n\nAdvance `i` by size + 2, or derive the bound from `data` rather than keeping a second counter."
    }
  ],
  "lastModified": "2026-09-29T19:17:21.203",
  "sourceIdentifier": "emo@eclipse.org"
}