Skip to content
Fencer Vulns
medium 6.5

CVE-2020-28388 json

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

published 2021-02-09 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-20847

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 72%
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 ReadyStart V3 (All versions < V2012.12), Nucleus Source Code (All versions), PLUSCONTROL 1st Gen (All versions), TALON TC Compact (BACnet) (All versions < V3.5.5), TALON TC Modular (BACnet) (All versions < V3.5.5). Initial Sequence Numbers (ISNs) for TCP connections are derived from an insufficiently random source. As a result, the ISN of current and future TCP connections could be predictable. An attacker could hijack existing sessions or spoof future ones.

Patch / fix

  • siemens nucleus_net 5.2
  • siemens nucleus_readystart 2012.12

Vendor advisories

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

cisa ICSA-22-349-16 updated cvss 6.5

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

cisa ICSA-21-042-01 updated cvss 6.5

Multiple Embedded TCP/IP Stacks (Update B)

  • multiple Capital VSTAR multiple CycloneTCP <= 1.9.6 multiple FNET 4.6.3 multiple MPLAB Net <= 3.6.1 multiple NDKTCPIP <= 2.25 multiple Nucleus NET All < 5.2
    +9 more products
    multiple Nucleus ReadyStart for ARM MIPS and PPC < 2012.12 multiple Nucleus Source Code multiple Nut/Net <= 5.1 multiple picoTCP (EOL) <= 1.7.0 multiple picoTCP-NG <= 1.7.0 multiple uC/TCP-IP (EOL) <= 3.6.0 multiple uIP (EOL) <= 1.0 multiple uIP-Contiki-NG <= 4.5 multiple uIP-Contiki-OS (end-of-life [EOL]) <= 3.0
    affected: vendor fix, mitigation “uIP-Contiki-OS (end-of-life [EOL]). See general recommendations below.” github.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

cisa ICSA-21-068-08 updated cvss 6.5

Siemens Energy PLUSCONTROL 1st Gen

  • Siemens PLUSCONTROL 1st Gen
    affected: mitigation

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

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

1.37% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L/E:P/RL:O/RC:C
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

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 ReadyStart V3
  • Siemens Nucleus Source Code
  • Siemens PLUSCONTROL 1st Gen
  • Siemens TALON TC Compact (BACnet)
  • Siemens TALON TC Modular (BACnet)

Classification

Weakness
  • CWE-342 Predictable Exact Value from Previous Values

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.