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Fencer Intel
medium 6.5

CVE-2020-12521 json

Phoenix Contact PLCnext Control Devices versions before 2021.0 LTS: A specially crafted LLDP packet may lead to a high system load in the PROFINET stack.

published 5y ago modified 4mo ago also EUVD-2020-4823

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

On Phoenix Contact PLCnext Control Devices versions before 2021.0 LTS a specially crafted LLDP packet may lead to a high system load in the PROFINET stack. An attacker can cause failure of system services or a complete reboot.

Patch / fix

  • Phoenix Contact AXC F 1152 (1151412) 2021.0 LTS
  • Phoenix Contact AXC F 2152 (2404267) 2021.0 LTS
  • Phoenix Contact AXC F 3152 (1069208) 2021.0 LTS
  • Phoenix Contact RFC 4072S (1051328 2021.0 LTS
  • Phoenix Contact AXC F 2152 Starterkit (1046568) 2021.0 LTS
  • Phoenix Contact PLCnext Technology Starterkit (1188165) 2021.0 LTS

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Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 6.1 AV:A/AC:L/Au:N/C:N/I:N/A:C

Affected products

  • Phoenix Contact AXC F 1152 (1151412)
  • Phoenix Contact AXC F 2152 (2404267)
  • Phoenix Contact AXC F 3152 (1069208)
  • Phoenix Contact RFC 4072S (1051328
  • Phoenix Contact AXC F 2152 Starterkit (1046568)
  • Phoenix Contact PLCnext Technology Starterkit (1188165)

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel 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.