CVE-2024-7515 Overview
CVE-2024-7515 is a denial-of-service vulnerability affecting multiple Rockwell Automation Logix controller families. A malformed Precision Time Protocol (PTP) management packet sent over the network causes a major nonrecoverable fault in the controller. The fault halts process execution and requires manual intervention to restore operations. The flaw is classified under CWE-20: Improper Input Validation and impacts firmware version 35.011 across the CompactLogix, ControlLogix, GuardLogix, and Compact GuardLogix product lines.
Critical Impact
An unauthenticated attacker with network access to the controller can trigger a nonrecoverable fault, stopping industrial control processes and forcing operator intervention to recover.
Affected Products
- Rockwell Automation CompactLogix 5380 and CompactLogix 5480 firmware 35.011
- Rockwell Automation ControlLogix 5580 firmware 35.011
- Rockwell Automation GuardLogix 5580, Compact GuardLogix 5380 SIL 2, and Compact GuardLogix 5380 SIL 3 firmware 35.011
Discovery Timeline
- 2024-08-14 - CVE-2024-7515 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-7515
Vulnerability Analysis
The vulnerability resides in the PTP management packet processing path of the affected Logix controller firmware. PTP (IEEE 1588) is used to synchronize clocks across networked industrial devices and is commonly enabled by default on these controllers. When the controller parses a malformed PTP management message, the firmware fails to validate the packet structure correctly, triggering a major nonrecoverable fault.
A major nonrecoverable fault on a Logix controller halts program execution and places the controller into a faulted state. Recovery requires manual intervention from an engineer or operator, including clearing the fault condition and potentially reloading the controller program. The impact on operational technology environments is direct: production lines, safety-instrumented functions, and process control loops dependent on the affected controller stop until the device is recovered.
Root Cause
The root cause is improper input validation of PTP management packets [CWE-20]. The firmware does not adequately sanitize or bound-check fields within the inbound PTP message before processing, allowing a single malformed packet to drive the controller into an unrecoverable fault state.
Attack Vector
Exploitation requires only network reachability to the controller. No authentication or user interaction is needed. An attacker on the same network segment, or with routed access to the controller's PTP interface, can craft and send the malformed packet using standard IP networking tools. Because PTP traffic typically traverses the same operational network as the controller's other industrial protocols, segmentation gaps directly expand the attack surface.
No public proof-of-concept code or in-the-wild exploitation has been reported for this vulnerability at the time of writing.
Detection Methods for CVE-2024-7515
Indicators of Compromise
- Unexpected major nonrecoverable faults on CompactLogix, ControlLogix, GuardLogix, or Compact GuardLogix controllers running firmware 35.011.
- Loss of communication or program execution on Logix controllers correlated with inbound PTP traffic from untrusted sources.
- PTP management messages originating from hosts that are not part of the documented time synchronization architecture.
Detection Strategies
- Monitor industrial network traffic for PTP management packets (UDP ports 319 and 320, or Ethernet type 0x88F7) sourced from unauthorized devices.
- Deploy ICS-aware network intrusion detection signatures that flag malformed or oversized PTP message fields.
- Correlate controller fault events from FactoryTalk or controller logs with packet capture data taken at the network boundary.
Monitoring Recommendations
- Capture and baseline normal PTP traffic patterns, including expected master and slave devices, to identify anomalous senders.
- Forward controller diagnostic and fault logs to a centralized SIEM or data lake for correlation with network telemetry.
- Alert on any controller transition into a faulted state and treat repeated faults as a potential exploitation indicator.
How to Mitigate CVE-2024-7515
Immediate Actions Required
- Inventory all Logix controllers and identify devices running firmware 35.011 listed in the Rockwell Automation Security Advisory SD1686.
- Apply the firmware update published by Rockwell Automation for each affected controller family.
- Restrict network access to controllers using firewalls and VLAN segmentation, blocking PTP traffic from untrusted segments.
- Verify that controllers are not exposed to the internet or to enterprise IT networks without inspection.
Patch Information
Rockwell Automation has released updated firmware addressing CVE-2024-7515. Refer to the Rockwell Automation Security Advisory SD1686 for the corrected firmware versions for each product family and follow vendor-approved upgrade procedures. Schedule patching during planned maintenance windows because firmware updates require controller downtime.
Workarounds
- Disable PTP on controllers where time synchronization is not operationally required.
- Place controllers behind ICS-aware firewalls and limit PTP communication to a defined list of trusted grandmaster clocks.
- Implement network segmentation aligned with the Purdue Reference Model to isolate Level 1 and Level 2 devices from broader networks.
- Monitor controller health continuously and prepare incident response playbooks to recover faulted controllers quickly.
# Example: block inbound PTP management traffic to controllers at a Linux firewall
# PTP event messages: UDP/319, PTP general messages: UDP/320
iptables -A FORWARD -p udp --dport 319 -s 0.0.0.0/0 -d <controller_subnet> -j DROP
iptables -A FORWARD -p udp --dport 320 -s 0.0.0.0/0 -d <controller_subnet> -j DROP
# Allow only an authorized PTP grandmaster
iptables -I FORWARD -p udp --dport 319 -s <trusted_ptp_master_ip> -d <controller_subnet> -j ACCEPT
iptables -I FORWARD -p udp --dport 320 -s <trusted_ptp_master_ip> -d <controller_subnet> -j ACCEPT
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
