{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2018-25241/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[{"cvss":7.5,"id":"CVE-2018-25241"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["medium"],"_cs_tags":["dos","cve-2018-25241","microsoft"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eMicrosoft VPN Browser+ version 1.1.0.0 is susceptible to a denial-of-service (DoS) vulnerability (CVE-2018-25241). This vulnerability allows an unauthenticated attacker to crash the application by providing an overly large input string to the search functionality. The application fails to handle the oversized input correctly, leading to an unhandled exception and subsequent termination. This poses a risk to users relying on the application for VPN services, as it can be easily disrupted without requiring any form of authentication. The vulnerability was reported in April 2026.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable instance of Microsoft VPN Browser+ 1.1.0.0.\u003c/li\u003e\n\u003cli\u003eThe attacker opens the application interface.\u003c/li\u003e\n\u003cli\u003eThe attacker locates the search bar within the application.\u003c/li\u003e\n\u003cli\u003eThe attacker pastes an extremely large string (e.g., several megabytes) into the search bar.\u003c/li\u003e\n\u003cli\u003eThe application attempts to process the oversized search query.\u003c/li\u003e\n\u003cli\u003eDue to inadequate input validation, the application triggers an unhandled exception.\u003c/li\u003e\n\u003cli\u003eThe exception leads to the immediate termination of the Microsoft VPN Browser+ process.\u003c/li\u003e\n\u003cli\u003eThe user experiences a denial of service as the application is no longer running.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this vulnerability results in a denial-of-service condition, rendering the Microsoft VPN Browser+ application unusable. Users relying on the application for VPN connectivity will be unable to establish or maintain secure connections, potentially exposing them to security risks. While the impact is limited to denial of service, the ease of exploitation and lack of authentication requirements make it a notable concern. The number of affected users depends on the adoption rate of Microsoft VPN Browser+ 1.1.0.0.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMonitor application logs for crashes associated with unusually large search queries to detect potential exploitation attempts (application logs).\u003c/li\u003e\n\u003cli\u003eImplement input validation and sanitization on the search functionality to prevent processing of oversized input strings.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule to detect processes crashing after large input to the Microsoft VPN Browser+ search (Sigma rule).\u003c/li\u003e\n\u003cli\u003eConsider upgrading or patching Microsoft VPN Browser+ to a version that addresses this vulnerability, if available (CVE-2018-25241).\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-04T14:16:19Z","date_published":"2026-04-04T14:16:19Z","id":"/briefs/2026-04-ms-vpn-dos/","summary":"An unauthenticated attacker can cause a denial of service by crashing Microsoft VPN Browser+ 1.1.0.0 via oversized input to the search functionality, leading to application termination.","title":"Microsoft VPN Browser+ 1.1.0.0 Denial of Service Vulnerability (CVE-2018-25241)","url":"https://feed.craftedsignal.io/briefs/2026-04-ms-vpn-dos/"}],"language":"en","title":"CraftedSignal Threat Feed — Cve-2018-25241","version":"https://jsonfeed.org/version/1.1"}