CVE-2024-6199 is a classic buffer overflow vulnerability (CWE-120) identified in the ViaSat RM5110 modem. The vulnerability arises due to improper handling of input size during buffer copy operations related to Dynamic DNS (DDNS) traffic processing. Specifically, an unauthenticated attacker positioned on the WAN interface can intercept and manipulate DDNS responses sent between the DDNS service and the modem. By crafting malicious DDNS responses containing oversized payloads, the attacker can trigger a buffer overflow condition within the modem's firmware. This overflow can potentially lead to arbitrary code execution, denial of service, or device compromise. Importantly, exploitation does not require authentication or user interaction, but it does require the attacker to be able to intercept or manipulate DDNS traffic, which implies some level of network access or man-in-the-middle capability on the WAN side. Devices that do not have Dynamic DNS enabled are not vulnerable, as the attack vector depends on processing DDNS responses. No public exploits are currently known in the wild, and no patches have been published yet. The vulnerability was reserved in June 2024 and publicly disclosed in April 2025. The affected product, ViaSat RM5110, is a satellite modem commonly used for broadband internet access, especially in remote or rural areas where terrestrial infrastructure is limited. The vulnerability's root cause is a failure to validate input size before copying data into a fixed-size buffer, a well-known and historically critical class of vulnerabilities that can lead to severe security consequences if exploited.

For European organizations, the impact of this vulnerability could be significant, particularly for those relying on ViaSat RM5110 modems for satellite internet connectivity. Potential impacts include unauthorized remote code execution, which could allow attackers to take control of the modem, intercept or manipulate network traffic, or pivot into internal networks. This could compromise confidentiality, integrity, and availability of organizational data and services. Critical infrastructure providers, remote offices, and enterprises in rural or underserved regions using satellite connectivity are at heightened risk. The vulnerability could also be leveraged to disrupt internet connectivity by causing modem crashes or reboots, leading to denial of service. Given the unauthenticated nature of the exploit and the lack of user interaction requirements, the attack surface is broad for any exposed WAN interfaces with DDNS enabled. However, the need to intercept or manipulate DDNS traffic somewhat limits the ease of exploitation to attackers with network positioning capabilities. The absence of known exploits in the wild and patches means organizations currently face a window of exposure. Overall, the vulnerability poses a medium risk but could escalate if weaponized in targeted attacks against critical sectors such as energy, transportation, or government agencies relying on satellite communications.

1. Immediate mitigation involves disabling Dynamic DNS on all ViaSat RM5110 modems if it is not strictly required, as devices without DDNS enabled are not vulnerable. 2. For environments where DDNS is essential, implement network-level protections such as strict filtering and monitoring of DDNS traffic to detect and block anomalous or manipulated responses. 3. Employ network segmentation to isolate satellite modem WAN interfaces from critical internal networks to limit potential lateral movement in case of compromise. 4. Use encrypted and authenticated DDNS services if supported, to prevent interception and tampering of DDNS traffic. 5. Monitor modem logs and network traffic for unusual patterns indicative of exploitation attempts, including unexpected reboots or malformed DDNS responses. 6. Engage with ViaSat and vendors for timely firmware updates or patches addressing this vulnerability and plan for rapid deployment once available. 7. Consider deploying intrusion detection/prevention systems (IDS/IPS) with signatures targeting buffer overflow attempts or malformed DDNS packets specific to this vulnerability. 8. Conduct regular security assessments of satellite communication infrastructure to identify and remediate similar weaknesses proactively.