{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/weak-cryptography/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":9.3,"id":"CVE-2026-63089"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["WireGuard Easy (\u003c= 15.3.0)"],"_cs_severities":["critical"],"_cs_tags":["vulnerability","cve","weak-cryptography","credential-access","initial-access","web"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eUnauthenticated network attackers can leverage a critical vulnerability, CVE-2026-63089, present in WireGuard Easy versions up to 15.3.0. The vulnerability stems from a cryptographically weak one-time link token generation mechanism, which utilizes CRC32 over a limited random value (0-999), resulting in a small keyspace of at most 1000 candidate tokens per client ID. Attackers can exploit this by brute-forcing tokens against the unauthenticated \u003ccode\u003e/cnf/:oneTimeLink\u003c/code\u003e route, which lacks rate limiting and does not validate token expiration. Successful brute-force allows the recovery of a WireGuard peer's PrivateKey and PresharedKey, enabling the attacker to impersonate a legitimate peer and gain unauthorized access to the VPN network. This vulnerability has been addressed in commit 66b292b.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn unauthenticated attacker identifies a WireGuard Easy instance vulnerable to CVE-2026-63089, exposed via a public-facing network.\u003c/li\u003e\n\u003cli\u003eThe attacker sends HTTP GET requests to the unauthenticated \u003ccode\u003e/cnf/:oneTimeLink\u003c/code\u003e endpoint of the vulnerable WireGuard Easy instance.\u003c/li\u003e\n\u003cli\u003eThe attacker brute-forces the one-time link token, iterating through the small keyspace of 0-999 candidates per client ID, leveraging the CRC32 algorithm used for token generation.\u003c/li\u003e\n\u003cli\u003eDue to the lack of rate-limiting on the \u003ccode\u003e/cnf/:oneTimeLink\u003c/code\u003e route, the attacker can submit numerous token guesses rapidly without being blocked.\u003c/li\u003e\n\u003cli\u003eUpon a successful token guess, the WireGuard Easy instance responds with the target WireGuard peer's \u003ccode\u003ePrivateKey\u003c/code\u003e and \u003ccode\u003ePresharedKey\u003c/code\u003e credentials.\u003c/li\u003e\n\u003cli\u003eThe attacker configures their own WireGuard client using the stolen \u003ccode\u003ePrivateKey\u003c/code\u003e and \u003ccode\u003ePresharedKey\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eThe attacker establishes a connection to the WireGuard VPN server, impersonating the legitimate peer.\u003c/li\u003e\n\u003cli\u003eThrough the impersonated peer's VPN session, the attacker gains unauthorized network access to internal resources behind the VPN.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-63089 leads to complete compromise of WireGuard peer credentials (PrivateKey and PresharedKey). Attackers can then impersonate legitimate users or devices on the VPN network, bypassing security controls and gaining unauthorized access to internal systems and sensitive data. This can lead to broader network compromise, data exfiltration, system disruption, and potentially ransomware deployment, depending on the attacker's objectives and the resources accessible via the compromised VPN. The CVSS v3.1 Base Score of 9.3 indicates critical severity and potential for widespread damage.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePatch CVE-2026-63089 immediately by upgrading WireGuard Easy to a version containing commit 66b292b or later.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026quot;Detect HTTP GET Requests to WireGuard Easy One-Time Link Endpoint\u0026quot; to your SIEM and tune for your environment to alert on requests to \u003ccode\u003e/cnf/:oneTimeLink\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eBlock the URL path \u003ccode\u003e/cnf/:oneTimeLink\u003c/code\u003e at the web application firewall or network edge if it is not legitimately used in your deployment, especially if the vulnerable version is still in use.\u003c/li\u003e\n\u003cli\u003eReview web server logs for suspicious activity related to the \u003ccode\u003e/cnf/:oneTimeLink\u003c/code\u003e path, looking for high volumes of requests from unusual source IPs, which could indicate brute-force attempts targeting the vulnerability.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-16T20:22:53Z","date_published":"2026-07-16T20:22:53Z","id":"https://feed.craftedsignal.io/briefs/2026-07-cve-2026-63089-wireguard-easy/","summary":"Unauthenticated network attackers can exploit a cryptographically weak one-time link token generation vulnerability, CVE-2026-63089, in WireGuard Easy through version 15.3.0 by brute-forcing a limited keyspace against the unauthenticated `/cnf/:oneTimeLink` route, allowing them to recover WireGuard peer credentials (PrivateKey and PresharedKey) and impersonate legitimate peers to gain unauthorized VPN access.","title":"CVE-2026-63089: WireGuard Easy Weak One-Time Link Token Generation Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-07-cve-2026-63089-wireguard-easy/"}],"language":"en","title":"CraftedSignal Threat Feed - Weak-Cryptography","version":"https://jsonfeed.org/version/1.1"}