Executive brief
Xerte Online Toolkits, an open-source platform for creating interactive learning materials, is vulnerable to a security flaw in its file management component. An attacker can exploit this to move files to unauthorized locations on the server, potentially leading to the theft of sensitive data or a complete takeover of the application. While the attack typically requires a valid username, it can be combined with other flaws to allow unauthorized users to execute malicious code on the system.
Technical details
A relative path traversal vulnerability exists in Xerte Online Toolkits (<= 3.15) within the elFinder connector endpoint located at /editor/elfinder/php/connector.php. The root cause is a failure to sanitize the 'name' parameter during 'rename' commands. An attacker with network access and a valid username (or by chaining with CVE-2026-34413 for unauthenticated access) can supply traversal sequences (e.g., ../) to move files from project media directories to the application root. When combined with incomplete file extension filtering (CVE-2026-34415), this allows an attacker to upload and move a malicious PHP file to the web root to achieve remote code execution. Patches have been backported to versions 3.13, 3.14, and 3.15.
Affected products
- The Xerte Project Xerte Online Toolkits <= 3.15
Timeline
- 2026-03-23: disclosed: Vulnerability reported to developers via GitHub issue
- 2026-04-22: advisory: CVE published by VulnCheck
- 2026-04-22: patched: Fixes committed to GitHub repository
References
- https://github.com/bootstrapbool/xerteonlinetoolkits-rce
- https://github.com/thexerteproject/xerteonlinetoolkits/commit/02661be88cc369325ea01b508086bde7fbfec805
- https://github.com/thexerteproject/xerteonlinetoolkits/commit/17e4f945fe6a3400fa88c01eda18c1075ee4a212
- https://github.com/thexerteproject/xerteonlinetoolkits/commit/507d55c5e91bf9310b5b1c7fad8aebfef902ad23
- https://github.com/thexerteproject/xerteonlinetoolkits/issues/1527
- https://www.vulncheck.com/advisories/xerte-online-toolkits-path-traversal-via-connector-php
- https://xerte.org.uk/index.php/en/downloads-1/category/3-xerte-online-toolkits