{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/elevation_of_privilege/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["SharePoint Server"],"_cs_severities":["critical"],"_cs_tags":["sharepoint","elevation_of_privilege","cve-2023-29357"],"_cs_type":"advisory","_cs_vendors":["Microsoft"],"content_html":"\u003cp\u003eThis brief addresses potential exploitation attempts targeting CVE-2023-29357, a Microsoft SharePoint Server elevation of privilege vulnerability. Successful exploitation could allow attackers to gain unauthorized privileged access to the SharePoint environment. The vulnerability is triggered by crafting specific API calls. The provided detection logic monitors web server logs for requests to specific SharePoint API endpoints associated with user management and current user information, specifically targeting GET requests with a 200 status code to the \u003ccode\u003e/api/web/siteusers\u003c/code\u003e and \u003ccode\u003e/api/web/currentuser\u003c/code\u003e paths. Exploitation could lead to unauthorized access to sensitive data, data theft, and further compromise of the SharePoint server, resulting in a broader security breach.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable SharePoint server exposed to the internet or an internal network.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP GET request targeting the \u003ccode\u003e/api/web/siteusers\u003c/code\u003e endpoint, aiming to retrieve a list of site users.\u003c/li\u003e\n\u003cli\u003eThe attacker sends the crafted HTTP GET request to the vulnerable SharePoint server.\u003c/li\u003e\n\u003cli\u003eThe SharePoint server processes the request without proper authorization checks due to the vulnerability.\u003c/li\u003e\n\u003cli\u003eThe server responds with a 200 OK status code, potentially returning sensitive information about site users, or granting elevated privileges.\u003c/li\u003e\n\u003cli\u003eThe attacker analyzes the response data, identifying privileged accounts or gaining insights into the SharePoint user structure.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the gained privileges to access sensitive data, modify SharePoint configurations, or further compromise the system.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2023-29357 can lead to a complete compromise of the SharePoint server. Attackers can gain unauthorized access to confidential documents, manipulate critical business data, and potentially use the compromised server as a pivot point for further attacks within the organization's network. The impact includes data breaches, financial losses, reputational damage, and disruption of business operations.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the provided Sigma rule to detect exploitation attempts against CVE-2023-29357 by monitoring for specific API calls (e.g., \u003ccode\u003e*/_api/web/siteusers*\u003c/code\u003e, \u003ccode\u003e*/_api/web/currentuser*\u003c/code\u003e) in web server logs.\u003c/li\u003e\n\u003cli\u003eReview and patch Microsoft SharePoint Servers to the latest version to remediate CVE-2023-29357, as referenced in the references section.\u003c/li\u003e\n\u003cli\u003eImplement network segmentation to limit the blast radius of a potential SharePoint compromise, as this helps contain lateral movement.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-02T12:00:00Z","date_published":"2024-01-02T12:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-sharepoint-eop/","summary":"Exploitation attempts against Microsoft SharePoint Server vulnerability CVE-2023-29357, involving specific API calls and HTTP methods, can lead to privilege escalation and unauthorized access to sensitive data within the SharePoint environment.","title":"Microsoft SharePoint Server Elevation of Privilege via CVE-2023-29357","url":"https://feed.craftedsignal.io/briefs/2024-01-sharepoint-eop/"}],"language":"en","title":"CraftedSignal Threat Feed - Elevation_of_privilege","version":"https://jsonfeed.org/version/1.1"}