ASUS Breach Incident Score: Analysis & Impact (ASU5132951111725)

In this Rankiteo incident briefing, we review the ASUS breach identified under incident ID ASU5132951111725.

The analysis begins with a detailed overview of ASUS's information like the linkedin page: https://www.linkedin.com/company/asus, the number of followers: 987332, the industry type: Computer Hardware Manufacturing and the number of employees: 16061 employees

After the initial compromise, the video explains how Rankiteo's incident engine converts technical details into a normalized incident score. The incident score before the incident was 771 and after the incident was 767 with a difference of -4 which is could be a good indicator of the severity and impact of the incident.

In the next step of the video, we will analyze in more details the incident and the impact it had on ASUS and their customers.

ASUS recently reported "Critical Authentication Bypass Flaw in ASUS DSL-Series Routers (CVE-2025-59367)", a noteworthy cybersecurity incident.

ASUS has issued new firmware updates to fix a critical authentication bypass flaw (CVE-2025-59367) affecting multiple DSL-series routers (DSL-AC51, DSL-N16, DSL-AC750).

The disruption is felt across the environment, affecting ASUS DSL-AC51, ASUS DSL-N16 and ASUS DSL-AC750.

In response, teams activated the incident response plan, moved swiftly to contain the threat with measures like Firmware update (version 1.1.2.3_1010) for DSL-AC51, DSL-N16, DSL-AC750, Disabling internet-accessible services (remote WAN, port forwarding, DDNS, VPN, DMZ, port triggering, FTP) for unpatchable devices and Recommending strong passwords, avoiding credential reuse, and regular update checks, and began remediation that includes Firmware patch and Security hardening guidance for end-of-life devices, and stakeholders are being briefed through Public advisory via ASUS support portal, Networking page notifications and Media outreach.

The case underscores how Ongoing (no confirmed in-the-wild exploitation reported), teams are taking away lessons such as Router vulnerabilities are high-value targets for botnet operators (e.g., Vicious Trap's AyySSHush campaign), End-of-life hardware poses persistent risks if not properly secured or decommissioned and Proactive firmware updates and service hardening are critical for mitigating authentication bypass flaws, and recommending next steps like Immediately apply firmware updates for affected ASUS DSL-series routers, Disable all internet-facing services (remote WAN, port forwarding, etc.) if patching is not feasible and Use strong, unique passwords for router administration and Wi-Fi networks, with advisories going out to stakeholders covering ASUS support portal notifications and Public security bulletin.

Finally, we try to match the incident with the MITRE ATT&CK framework to see if there is any correlation between the incident and the MITRE ATT&CK framework.

The MITRE ATT&CK framework is a knowledge base of techniques and sub-techniques that are used to describe the tactics and procedures of cyber adversaries. It is a powerful tool for understanding the threat landscape and for developing effective defense strategies.

Rankiteo's analysis has identified several MITRE ATT&CK tactics and techniques associated with this incident, each with varying levels of confidence based on available evidence. Under the Initial Access tactic, the analysis identified Exploit Public-Facing Application (T1190) with high confidence (95%), with evidence including unauthenticated remote attackers to bypass credentials and gain full administrative access, and cVE-2025-59367 (Authentication Bypass in DSL-series routers) and Valid Accounts (T1078) with moderate to high confidence (85%), supported by evidence indicating gain full administrative access via authentication bypass. Under the Persistence tactic, the analysis identified Valid Accounts: Local Accounts (T1078.003) with moderate to high confidence (80%), supported by evidence indicating full administrative access to router interfaces for persistent control and Pre-OS Boot: System Firmware (T1542.003) with moderate to high confidence (70%), supported by evidence indicating firmware update (version 1.1.2.3_1010) required to remediate, implying firmware-level persistence risk. Under the Privilege Escalation tactic, the analysis identified Exploitation for Privilege Escalation (T1068) with high confidence (90%), supported by evidence indicating bypass credentials and gain full administrative access via CVE-2025-59367. Under the Defense Evasion tactic, the analysis identified Impair Defenses: Disable or Modify Tools (T1562.001) with moderate to high confidence (75%), supported by evidence indicating disable internet-facing services (WAN access, port forwarding, VPN, DMZ) if unpatchable. Under the Command and Control tactic, the analysis identified Proxy: External Proxy (T1090.004) with moderate to high confidence (80%), with evidence including risk of router hijacking for botnets/DDoS campaigns (e.g., AyySSHush botnet), and port forwarding, VPN, DMZ as potential C2 channels. Under the Impact tactic, the analysis identified Network Denial of Service: Direct Network Flood (T1498.001) with moderate to high confidence (85%), with evidence including hijacked for botnet recruitment or DDoS campaigns, and vicious Trap group exploiting older ASUS flaws for AyySSHush botnet and Resource Hijacking (T1496) with moderate to high confidence (80%), with evidence including routers being hijacked for botnets, and large-scale device compromise. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.