CVE-2025-7048 Overview
On affected platforms running Arista EOS with MACsec configuration, a specially crafted packet can cause the MACsec process to terminate unexpectedly. Continuous receipt of these packets with certain MACsec configurations can cause longer term disruption of dataplane traffic. This vulnerability represents a Denial of Service condition that could impact network availability for organizations relying on MACsec-protected network segments.
Critical Impact
Attackers on an adjacent network can cause persistent dataplane traffic disruption by sending crafted packets to systems running Arista EOS with MACsec enabled, potentially impacting network availability across affected infrastructure.
Affected Products
- Arista EOS platforms with MACsec configuration enabled
Discovery Timeline
- 2026-01-06 - CVE CVE-2025-7048 published to NVD
- 2026-01-08 - Last updated in NVD database
Technical Details for CVE-2025-7048
Vulnerability Analysis
This vulnerability is classified under CWE-805 (Buffer Access with Incorrect Length Value), indicating that the MACsec process improperly handles buffer boundaries when processing incoming packets. The flaw exists in how Arista EOS processes MACsec-related network traffic, where a specially crafted packet can trigger unexpected process termination.
The vulnerability requires adjacent network access, meaning an attacker must be on the same network segment as the target device. No authentication or user interaction is required to exploit this vulnerability, making it relatively straightforward for attackers who have already gained access to the local network.
Root Cause
The root cause is related to CWE-805: Buffer Access with Incorrect Length Value. The MACsec process in Arista EOS fails to properly validate buffer lengths when processing incoming packets. When a malformed packet with unexpected length values is received, the process attempts to access memory outside the intended buffer boundaries, causing the MACsec process to crash. This improper boundary checking allows attackers to repeatedly trigger process termination, leading to sustained denial of service.
Attack Vector
The attack requires adjacent network access, meaning the attacker must be positioned on the same Layer 2 network segment as the target Arista EOS device. The attacker can send specially crafted packets without requiring any authentication or privileges. When these malicious packets reach a vulnerable device with MACsec enabled, the MACsec process terminates unexpectedly.
By continuously sending these crafted packets, an attacker can cause persistent disruption of dataplane traffic, as the MACsec process repeatedly crashes and restarts. This can effectively degrade or deny network services for traffic that relies on the MACsec-protected interfaces.
For detailed technical information, refer to the Arista Security Advisory #0132.
Detection Methods for CVE-2025-7048
Indicators of Compromise
- Unexpected MACsec process restarts or terminations in system logs
- Repeated dataplane traffic disruptions on MACsec-enabled interfaces
- Unusual patterns of traffic from adjacent network devices targeting MACsec interfaces
- System alerts indicating MACsec service instability
Detection Strategies
- Monitor Arista EOS system logs for MACsec process crashes or unexpected restarts
- Implement network monitoring to detect anomalous traffic patterns on MACsec-enabled interfaces
- Configure alerting for repeated MACsec process failures within short time windows
- Deploy network intrusion detection systems to identify potential exploitation attempts
Monitoring Recommendations
- Enable detailed logging for MACsec process events on all affected Arista EOS devices
- Establish baseline metrics for MACsec process stability and alert on deviations
- Monitor network traffic on adjacent segments for suspicious packet patterns
- Review system health dashboards regularly for signs of service instability
How to Mitigate CVE-2025-7048
Immediate Actions Required
- Review all Arista EOS devices in your environment for MACsec configurations
- Consult the Arista Security Advisory for affected software versions and recommended updates
- Prioritize patching devices that are accessible from less trusted network segments
- Consider network segmentation to limit adjacent network access to MACsec-enabled interfaces
Patch Information
Arista has released information regarding this vulnerability in their Security Advisory #0132. Organizations should review this advisory to identify affected software versions and obtain the appropriate patches. Ensure that all Arista EOS devices with MACsec configurations are updated to patched versions as soon as possible.
Workarounds
- Evaluate whether MACsec can be temporarily disabled on non-critical interfaces until patches are applied
- Implement strict network access controls to limit which devices can reach MACsec-enabled interfaces
- Apply ACLs to filter potentially malicious traffic from untrusted adjacent network segments
- Increase monitoring and alerting sensitivity for MACsec-related events
# Configuration example - Network ACL to restrict access to MACsec interfaces
# Consult Arista documentation for specific syntax and options
# Review Security Advisory #0132 for recommended mitigations:
# https://www.arista.com/en/support/advisories-notices/security-advisory/23120-security-advisory-0132
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
