{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-39942/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":8.5,"id":"CVE-2026-39942"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Directus"],"_cs_severities":["high"],"_cs_tags":["directus","file-overwrite","privilege-escalation","CVE-2026-39942"],"_cs_type":"advisory","_cs_vendors":["Directus"],"content_html":"\u003cp\u003eDirectus is a real-time API and App dashboard used for managing SQL database content. A vulnerability, identified as CVE-2026-39942, affects versions of Directus prior to 11.17.0. The vulnerability lies in the PATCH /files/{id} endpoint, which improperly handles the filename_disk parameter. A malicious actor can exploit this by crafting a request that sets the filename_disk parameter to the storage path of another user's file. Successful exploitation allows the attacker to overwrite the targeted file's content, potentially corrupting data or gaining unauthorized access. Additionally, the attacker can manipulate metadata fields like uploaded_by to obscure the tampering, making detection more challenging. Upgrading to version 11.17.0 or later resolves this vulnerability.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker identifies a vulnerable Directus instance running a version prior to 11.17.0.\u003c/li\u003e\n\u003cli\u003eAttacker authenticates to the Directus instance with a valid user account.\u003c/li\u003e\n\u003cli\u003eAttacker identifies the target file's storage path on the disk. This might involve enumeration or prior knowledge of the file system structure.\u003c/li\u003e\n\u003cli\u003eAttacker crafts a malicious PATCH request to the /files/{id} endpoint, where {id} is the ID of a file they control.\u003c/li\u003e\n\u003cli\u003eIn the PATCH request body, the attacker sets the filename_disk parameter to the storage path of the target file they wish to overwrite.\u003c/li\u003e\n\u003cli\u003eThe attacker also manipulates other metadata fields, such as uploaded_by, to disguise their actions in audit logs.\u003c/li\u003e\n\u003cli\u003eThe Directus server processes the PATCH request, overwriting the content of the target file with the attacker's controlled data.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves the objective of overwriting the target file, potentially leading to data corruption, privilege escalation (if the overwritten file is an executable or configuration file), or defacement.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-39942 allows an attacker to overwrite arbitrary files within the Directus instance's storage directory. This could lead to data corruption, where legitimate files are replaced with malicious content. If the overwritten file is an executable or configuration file, the attacker could potentially achieve privilege escalation, allowing them to gain control of the Directus instance or the underlying server. Furthermore, the attacker's ability to manipulate metadata fields makes it difficult to trace the malicious activity, hindering incident response efforts. The number of potential victims depends on the prevalence of vulnerable Directus instances.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eImmediately upgrade Directus to version 11.17.0 or later to patch CVE-2026-39942.\u003c/li\u003e\n\u003cli\u003eImplement the Sigma rule \u0026quot;Detect Directus File Overwrite Attempt via PATCH Request\u0026quot; to detect attempts to exploit this vulnerability by monitoring PATCH requests to the /files endpoint with suspicious filename_disk parameters.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for PATCH requests to the /files endpoint (webserver logs) with unusual filename_disk values that deviate from expected patterns.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T10:00:00Z","date_published":"2024-01-03T10:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-directus-file-overwrite/","summary":"A file overwrite vulnerability (CVE-2026-39942) exists in Directus versions prior to 11.17.0, where an attacker can overwrite another user's files by manipulating the filename_disk parameter in the PATCH /files/{id} endpoint, potentially leading to data corruption or privilege escalation.","title":"Directus File Overwrite Vulnerability (CVE-2026-39942)","url":"https://feed.craftedsignal.io/briefs/2024-01-directus-file-overwrite/"}],"language":"en","title":"CraftedSignal Threat Feed - CVE-2026-39942","version":"https://jsonfeed.org/version/1.1"}