CVE-2025-61128 is a stack-based buffer overflow vulnerability identified in the firmware version M30HG3_V240730 of the WAVLINK QUANTUM D3G/WL-WN530HG3 wireless router, with indications that other WAVLINK models may also be affected. The vulnerability arises from improper handling of the referrer HTTP header value in POST requests directed at the login.cgi endpoint. An attacker can craft a malicious referrer value that overflows a stack buffer, enabling arbitrary code execution on the device. This type of vulnerability is critical because it allows remote attackers to gain control over the affected device without authentication, potentially bypassing security controls. The lack of a CVSS score suggests the vulnerability is newly published, with no known exploits in the wild yet. However, the nature of stack-based buffer overflows typically allows for remote code execution, which can lead to device takeover, network pivoting, and further compromise of connected systems. The vulnerability affects firmware used in consumer and possibly enterprise-grade network devices, which are often deployed in small office/home office (SOHO) environments and potentially in enterprise edge networks. The absence of patch links indicates that a vendor fix may not yet be available, increasing the urgency for interim mitigations. Attackers exploiting this flaw could disrupt network availability, intercept or manipulate traffic, and compromise network confidentiality and integrity.

For European organizations, the impact of CVE-2025-61128 could be significant, especially for those using WAVLINK QUANTUM D3G/WL-WN530HG3 or related models in their network infrastructure. Successful exploitation would allow attackers to execute arbitrary code remotely, potentially leading to full device compromise. This can result in unauthorized access to internal networks, interception of sensitive data, disruption of network services, and use of compromised devices as footholds for further attacks. Organizations in sectors such as finance, healthcare, government, and critical infrastructure could face severe operational and reputational damage. The vulnerability also poses risks to supply chain security if WAVLINK devices are used by managed service providers or in multi-tenant environments. Given the lack of authentication requirement and the remote nature of the attack vector, the threat is elevated. Additionally, the absence of known exploits currently does not preclude rapid development of exploit code once the vulnerability details become widely known, increasing the urgency for proactive defense.

1. Immediately inventory all WAVLINK devices in use, focusing on the QUANTUM D3G/WL-WN530HG3 and related models. 2. Monitor vendor communications closely for firmware updates or patches addressing CVE-2025-61128 and apply them promptly once available. 3. Until patches are released, implement network-level mitigations such as blocking or filtering HTTP POST requests with suspicious or unusual referrer headers targeting login.cgi endpoints on WAVLINK devices. 4. Segment networks to isolate vulnerable devices from critical infrastructure and sensitive data environments to limit lateral movement in case of compromise. 5. Enable and review device logs and network monitoring tools to detect anomalous POST requests or unexpected device behavior indicative of exploitation attempts. 6. Consider replacing high-risk devices with alternative hardware from vendors with stronger security track records if patching is delayed. 7. Educate IT and security teams about this vulnerability and ensure incident response plans include steps for potential exploitation scenarios involving network devices. 8. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics that can detect buffer overflow attempts or malformed HTTP headers targeting login.cgi.