Unauthenticated service crash via unbounded URI parsing
Published Jul 23, 2025 · Updated Feb 26, 2026
Stack-based buffer overflow in SonicWall SMA 100 Series 10.2.1.15-81sv and earlier allows remote attackers to crash the web service. The EasyAccess httpd handler uses sscanf to copy an unbounded /api/ URI suffix into a 0x800-byte stack buffer. No authentication or user interaction is required; stack protection makes code execution difficult, while the demonstrated oversized request interrupts service.
Summary
What happened
Stack-based buffer overflow in SonicWall SMA 100 Series 10.2.1.15-81sv and earlier allows remote attackers to crash the web service. The EasyAccess httpd handler uses sscanf to copy an unbounded /api/ URI suffix into a 0x800-byte stack buffer. No authentication or user interaction is required; stack protection makes code execution difficult, while the demonstrated oversized request interrupts service.
The record
- CVE
- CVE-2025-40596
- Published
- Jul 23, 2025
- Updated
- Feb 26, 2026
- Vendor
- SonicWall
- Product
- Secure Mobile Access (SMA) 100 Series
- Classifications
- CWE-121, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 23, 2025CVE publishedPublication date reported by the CVE source.
- Feb 26, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.2.1.15-81sv and earlier versions
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- watchTowr SMA100 API URI crash proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo