{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-40909/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":8.7,"id":"CVE-2026-40909"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["AVideo"],"_cs_severities":["critical"],"_cs_tags":["avideo","rce","cve-2026-40909"],"_cs_type":"advisory","_cs_vendors":["WWBN"],"content_html":"\u003cp\u003eWWBN AVideo, an open source video platform, is susceptible to remote code execution in versions 29.0 and earlier. The vulnerability, identified as CVE-2026-40909, stems from the \u003ccode\u003elocale/save.php\u003c/code\u003e endpoint. This endpoint constructs a file path by directly concatenating the \u003ccode\u003e$_POST['flag']\u003c/code\u003e parameter into the path without sanitization at line 30. Subsequently, the \u003ccode\u003e$_POST['code']\u003c/code\u003e parameter is written verbatim to the generated path via \u003ccode\u003efwrite()\u003c/code\u003e at line 40. This lack of input validation allows an authenticated administrator, or an attacker capable of executing a cross-site request forgery (CSRF) attack against an administrator, to write arbitrary PHP files to any writable location on the filesystem, leading to arbitrary code execution. The vulnerable versions use \u003ccode\u003eSameSite=None\u003c/code\u003e for cookies and lack CSRF token checks, exacerbating the risk. The patch is available in commit 57f89ffbc27d37c9d9dd727212334846e78ac21a.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker authenticates to the AVideo platform as an administrator or gains the ability to perform actions as an administrator (e.g., through CSRF).\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP POST request targeting the \u003ccode\u003e/locale/save.php\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eIn the POST request, the attacker sets the \u003ccode\u003eflag\u003c/code\u003e parameter to a string containing directory traversal sequences (e.g., \u003ccode\u003e../../\u003c/code\u003e) to navigate to a writable directory outside of the intended \u003ccode\u003elocale/\u003c/code\u003e directory.\u003c/li\u003e\n\u003cli\u003eThe attacker sets the \u003ccode\u003ecode\u003c/code\u003e parameter to arbitrary PHP code that they want to execute on the server. This code can include web shells or other malicious payloads.\u003c/li\u003e\n\u003cli\u003eThe server receives the POST request and, due to the lack of sanitization, constructs a file path based on the attacker-controlled \u003ccode\u003eflag\u003c/code\u003e parameter.\u003c/li\u003e\n\u003cli\u003eThe server writes the contents of the \u003ccode\u003ecode\u003c/code\u003e parameter to the file path constructed in the previous step, creating a PHP file containing the attacker's malicious code.\u003c/li\u003e\n\u003cli\u003eThe attacker accesses the newly created PHP file via a web request, triggering the execution of the injected PHP code.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves remote code execution on the AVideo server, enabling them to perform actions such as installing malware, accessing sensitive data, or compromising the entire system.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-40909 allows an attacker to execute arbitrary PHP code on the AVideo server. This can lead to complete system compromise, including data theft, installation of malware, and denial of service. Given the nature of AVideo as a video platform, a successful attack could also result in the defacement of the website or the distribution of malicious content to users. The number of potential victims is directly proportional to the number of AVideo installations running vulnerable versions.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply the patch from commit 57f89ffbc27d37c9d9dd727212334846e78ac21a or upgrade to a version of AVideo greater than 29.0 to remediate CVE-2026-40909.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026quot;AVideo Locale Save Arbitrary File Write\u0026quot; to detect attempts to exploit this vulnerability via directory traversal in the \u003ccode\u003eflag\u003c/code\u003e parameter within web server logs.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for requests to \u003ccode\u003e/locale/save.php\u003c/code\u003e containing directory traversal sequences (\u003ccode\u003e../\u003c/code\u003e) in the POST parameters to identify potential exploitation attempts.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-23T12:00:00Z","date_published":"2024-01-23T12:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-23-avideo-rce/","summary":"AVideo versions 29.0 and prior are vulnerable to remote code execution due to unsanitized file path construction in the locale save endpoint, allowing arbitrary PHP file writes by authenticated administrators or those who can CSRF them.","title":"AVideo Remote Code Execution via Locale File Write","url":"https://feed.craftedsignal.io/briefs/2024-01-23-avideo-rce/"}],"language":"en","title":"CraftedSignal Threat Feed - Cve-2026-40909","version":"https://jsonfeed.org/version/1.1"}