CVE-2025-29229 identifies a command injection vulnerability in the Linksys E5600 router, specifically in firmware version 1.1.0.26 within the ddnsStatus function. Command injection vulnerabilities allow attackers to inject and execute arbitrary system commands on the affected device, often leading to full compromise. The ddnsStatus function likely processes dynamic DNS status information, and improper input validation or sanitization enables malicious input to be executed at the system level. The vulnerability does not require authentication, meaning attackers can exploit it remotely without credentials, increasing the attack surface significantly. Although no public exploits have been observed in the wild yet, the presence of such a flaw in a widely deployed consumer and small business router model is concerning. Attackers exploiting this vulnerability could gain control over the router, manipulate network traffic, intercept sensitive data, or use the device as a foothold for further attacks within an organization's network. The lack of a CVSS score limits precise severity quantification, but the nature of command injection and unauthenticated remote access suggests a high risk. No patches or vendor advisories are currently linked, indicating that mitigation options may be limited to workarounds or awaiting vendor response. The vulnerability was reserved in March 2025 and published in December 2025, suggesting recent discovery and disclosure. Organizations using Linksys E5600 routers should urgently assess exposure and implement compensating controls.

For European organizations, exploitation of this vulnerability could lead to significant network security breaches. Compromised routers can be used to intercept or redirect traffic, degrade network availability, or launch further attacks on internal systems. Small and medium enterprises relying on Linksys E5600 routers for internet connectivity and remote access are particularly vulnerable, as attackers could bypass perimeter defenses via the compromised device. Confidentiality of sensitive communications may be at risk, as well as the integrity and availability of network services. Critical infrastructure sectors that depend on secure and reliable network equipment could face operational disruptions. The unauthenticated nature of the vulnerability increases the likelihood of exploitation by external threat actors, including cybercriminals and state-sponsored groups. The absence of known exploits in the wild provides a window for proactive defense, but also means organizations may be unaware of the threat. Overall, the impact on European entities ranges from data breaches and espionage to service outages and reputational damage.

1. Immediately inventory and identify all Linksys E5600 routers within the organization to assess exposure. 2. Monitor vendor channels for firmware updates or security advisories addressing CVE-2025-29229 and apply patches as soon as they become available. 3. If patches are unavailable, disable the DDNS feature or the ddnsStatus function to prevent exploitation. 4. Restrict remote access to router management interfaces using firewall rules, VPNs, or network segmentation to limit exposure to untrusted networks. 5. Implement network monitoring to detect anomalous router behavior or unexpected command executions indicative of exploitation attempts. 6. Employ intrusion detection/prevention systems (IDS/IPS) with signatures targeting command injection patterns related to this vulnerability. 7. Educate IT staff about the vulnerability and ensure incident response plans include steps for compromised network devices. 8. Consider replacing vulnerable devices with models that have a stronger security posture if immediate patching is not feasible. 9. Regularly audit router configurations and logs to detect unauthorized changes or access. 10. Collaborate with ISPs and vendors to share threat intelligence and coordinate mitigation efforts.