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Fencer Vulns
high 8.1

CVE-2020-27009 json

A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions < V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions…

published 2021-04-22 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-19533

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
7.2%
EPSS 7.2% chance of exploitation in 30 days, percentile 94%
public exploits
0
none known

Summary

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 < V5.2), Nucleus Source Code (Versions including affected DNS modules), 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 write past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to execute code in the context of the current process or cause a denial-of-service condition.

Patch / fix

  • siemens nucleus_net 5.2

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-21-103-04 updated cvss 8.1

Siemens Nucleus Products DNS Module (Update A)

  • Siemens Nucleus NET <V5.2
    affected: workaround, mitigation, no fix planned
  • Siemens Nucleus Source Code including_affected_DNS_modules
    affected: vendor fix, workaround

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-22-349-16 updated cvss 8.1

Siemens APOGEE and TALON

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

7.19% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Siemens APOGEE PXC Compact (BACnet)
  • Siemens APOGEE PXC Compact (P2 Ethernet)
  • Siemens APOGEE PXC Modular (BACnet)
  • Siemens APOGEE PXC Modular (P2 Ethernet)
  • Siemens Nucleus NET
  • Siemens Nucleus Source Code
  • Siemens TALON TC Compact (BACnet)
  • Siemens TALON TC Modular (BACnet)

Classification

Weakness
  • CWE-823 Use of Out-of-range Pointer Offset
  • CWE-787 Out-of-bounds Write

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.