CVE-2020-12521 — On Phoenix Contact PLCnext Control Devices versions before 2021

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.

01What is this vulnerability?

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.

02Affected products

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

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2020-12-17T22:43:14.654Z
• Last modified: 2024-09-17T04:14:26.064Z

09References

• cert.vde.com — https://cert.vde.com/en-us/advisories/vde-2020-049