CVE-2020-12521
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.
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.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
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.
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.
- Record
CVE-2020-12521- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2020-4823
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.
- Record
EUVD-2020-4823- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-vp46-jgwp-q8w3 No score
On Phoenix Contact PLCnext Control Devices versions before 2021.0 LTS a specially crafted LLDP...
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.
- Record
GHSA-vp46-jgwp-q8w3- Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2020-12521- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 6.1 Medium
AV:A/AC:L/Au:N/C:N/I:N/A:C - Weakness
- CWE-20
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-12521 is a medium vulnerability (CVSS 6.5) in Phoenix Contact Axc F 1152 (1151412), published December 17, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.46%, the 40th percentile. No source names a fixed version.