Overview of SonicWall SMA100 SSL-VPN Vulnerabilities (CVE-2025-40596, CVE-2025-40597, CVE-2025-40598)

The user's description aligns closely with the reported details of these critical vulnerabilities affecting the web interface of SonicWall Secure Mobile Access (SMA) 100 series appliances, which provide SSL-VPN for remote access. These flaws enable unauthenticated attackers to trigger denial-of-service (DoS) conditions, potentially execute arbitrary code, or run malicious JavaScript. Discovered internally by SonicWall, patches were released on July 23, 2025, following routine security audits. While no confirmed in-the-wild exploitation has been reported as of July 24, 2025, the unauthenticated nature of the flaws has prompted warnings about likely active scanning by threat actors, as is common with newly disclosed remote access vulnerabilities. Organizations using SMA 100 series (e.g., 200, 210, 400, 410, 500v) are urged to patch immediately to mitigate risks of compromise.Key facts from reports:

• Vulnerability Details:
  • CVE-2025-40596: Stack-based buffer overflow in the web interface, allowing unauthenticated remote attackers to send crafted requests leading to DoS or potential remote code execution (RCE).
  • CVE-2025-40597: Heap-based buffer overflow with similar exploitation, enabling DoS or RCE via crafted inputs.
  • CVE-2025-40598: Reflected cross-site scripting (XSS) flaw, permitting unauthenticated attackers to inject and execute arbitrary JavaScript, potentially for phishing or session hijacking.
• Discovery and Timeline: Vulnerabilities were identified and patched by SonicWall on July 23, 2025. CVEs were assigned and published in NVD on the same day. No prior zero-day exploitation noted, but the rapid disclosure suggests proactive response to potential threats.
• Impact and Targets: Affects SMA 100 series appliances (versions from 10.2.0.2-20sv up to but not including the patched release). Potential for full system compromise via RCE in overflows (CVSS estimates around 8.1 critical), or client-side attacks via XSS (CVSS ~1.2-6.3 low to medium). Over 10,000 exposed SMA instances globally, primarily in enterprise and government sectors, making them attractive for ransomware or espionage.
• Exploitation Status: No public exploits, malware, or confirmed attacks as of now. However, reports indicate active scanning may be underway due to the flaws' remote, unauthenticated nature—similar to past SonicWall incidents where scanning surged post-disclosure. Security researchers and automated bots often probe new CVEs within hours.
• Response and Mitigations: SonicWall released patches via firmware updates (specific versions: upgrade to 10.2.1.15-81sv or later for related issues; confirm via advisory for exact). Recommendations include immediate patching, restricting web interface access to trusted IPs, enabling WAF/MFA, monitoring for anomalous traffic (e.g., crafted HTTP requests), and auditing logs for indicators like unexpected crashes or script injections. If patching is delayed, isolate appliances from the internet.

This incident follows a pattern of vulnerabilities in SonicWall SMA products, with prior chains leading to RCE in older versions. No addition to CISA's KEV catalog yet, but monitoring is advised. For detailed patch notes or PoC analysis (none public yet), refer to SonicWall's PSIRT resources