CVE-2020-27738

Estado: ModificadaAlta (7.4)—

A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions < V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.20), APOGEE PXC Modular (BACnet) (All versions < V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.20), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), TALON TC Compact (BACnet) (All versions < V3.5.5), TALON TC Modular (BACnet) (All versions < V3.5.5).

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The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
Puntuación base: 7.4

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 3.66%
Percentil entre todas las CVEs puntuadas: 89
Fecha de la puntuación: 6/10/2026

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).

Tecnologías afectadas (5)

Siemens — Nucleus NET Siemens — Nucleus Readystart V3 Siemens — Nucleus Readystart V4 Siemens — Nucleus Source Code Siemens — Simotics Connect 400 Firmware

CWE

CWE-788
CWE-119

Referencias

JSON original (NVD)

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      "value": "A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions < V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.20), APOGEE PXC Modular (BACnet) (All versions < V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.20), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.3), Nucleus ReadyStart V4 (All versions < V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions < V0.5.0.0), TALON TC Compact (BACnet) (All versions < V3.5.5), TALON TC Modular (BACnet) (All versions < V3.5.5). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition."
    },
    {
      "lang": "es",
      "value": "Se ha identificado una vulnerabilidad en Nucleus NET (Todas las versiones), Nucleus ReadyStart V3 (Todas las versiones anteriores a V2017.02.3), Nucleus ReadyStart V4 (Todas las versiones anteriores a V4.1.0), Nucleus Source Code (Versiones que incluyen los módulos DNS afectados), SIMOTICS CONNECT 400 (Todas las versiones anteriores a V0.5.0.0). La funcionalidad de descompresión de registros de nombres de dominio DNS no valida correctamente los valores de desplazamiento de puntero. El análisis sintáctico de respuestas malformadas podría dar lugar a un acceso de lectura más allá del final de una estructura asignada. Un atacante con una posición privilegiada en la red podría aprovechar esta vulnerabilidad para provocar una condición de denegación de servicio"
    }
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  "lastModified": "2026-06-17T03:09:32.927",
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