CVE-2018-25241
Published: 04 April 2026
Summary
CVE-2018-25241 is a high-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Microsoft (inferred from references). Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 27.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SC-5 (Denial-of-service Protection) and SI-10 (Information Input Validation).
Deeper analysis
CVE-2018-25241 is a denial-of-service vulnerability in VPN Browser+ version 1.1.0.0. The flaw arises from the application's failure to handle oversized input properly through its search functionality, leading to an unhandled exception that crashes the application. This issue is classified under CWE-306 and carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), indicating high availability impact with no confidentiality or integrity effects.
Unauthenticated attackers can exploit this vulnerability remotely over the network with low complexity and no user interaction required. By pasting a large buffer of characters into the search bar, an attacker triggers the unhandled exception, terminating the VPN Browser+ application and denying service to the user.
Advisories and references, including an Exploit-DB entry at https://www.exploit-db.com/exploits/46198 providing a proof-of-concept, the Microsoft Store product page at https://www.microsoft.com/store/productId/9NFFFFS5Z2C7, and a VulnCheck advisory at https://www.vulncheck.com/advisories/vpn-browser-denial-of-service, document the issue but do not specify patches or mitigations in the available details. Practitioners should verify updates for VPN Browser+ and consider avoiding version 1.1.0.0.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2018-21736
Vulnerability details
VPN Browser+ 1.1.0.0 contains a denial of service vulnerability that allows unauthenticated attackers to crash the application by submitting oversized input through the search functionality. Attackers can paste a large buffer of characters into the search bar to trigger an…
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unhandled exception that terminates the application.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct match to application exploitation causing endpoint DoS via unhandled oversized input crash.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
SI-10 directly prevents crashes by requiring validation of search functionality inputs to reject oversized buffers before processing.
SI-11 ensures unhandled exceptions from oversized inputs are managed gracefully without terminating the application.
SC-5 implements denial-of-service protections to limit the effects of oversized input attacks targeting application availability.