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CVE-2023-26482 affects Nextcloud Server. A missing scope validation flaw allowed non-administrative users to create workflows that should have been restricted to administrators. Because certain workflow types can invoke server-side functionality such as defined scripts, PDF generation helpers, webhooks, or other script execution paths, an attacker could abuse the authorization bypass to create privileged workflows. Depending on which apps are installed and enabled, particularly workflow-related apps that execute scripts or perform PDF conversion, this can be chained into remote code execution on the server.
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workflow_scripts and workflow_pdf_converter as a mitigation, as specifically recommended in the advisory.Patch, then assume compromise.
2 valid exploits after Mallory filtered fakes, detection scripts, and README-only repos.
Repository is a small Dockerized lab + Python PoC for Nextcloud Server CVE-2023-26482 (missing scope validation in workflow creation). Structure: (1) docker-compose.yml spins up MariaDB 10.6 and Nextcloud 25.0.3 exposed on host port 8080 with default admin credentials set via env vars. (2) setup.sh waits for Nextcloud readiness, installs/enables the 'workflow_script' app (required for command execution), and creates a non-admin user 'attacker' with password 'AttackerPassword123!'. (3) exploit.py uses requests.Session to: fetch /login, extract data-requesttoken, authenticate as attacker, then POST a JSON workflow definition to the OCS workflowengine API. It first targets the global workflows endpoint (/ocs/v2.php/.../workflows/global?format=json) to create an admin-scoped rule as a non-admin (the core of CVE-2023-26482). If that fails, it falls back to the user-scoped endpoint. The workflow payload uses class OCA\\WorkflowScript\\Operation with operation set to an OS command (default 'touch /tmp/pwned'), triggered on file creation events (\\OCP\\Files::postCreate) when the uploaded file MIME type is text/plain. Successful exploitation results in RCE in the Nextcloud container when any user uploads a .txt file, verifiable by checking for /tmp/pwned.
This repository contains a single Metasploit module (Ruby file) that exploits a remote code execution vulnerability (CVE-2023-26482) in the Nextcloud Workflow Script app. The exploit requires valid administrator credentials and the vulnerable app to be installed on the target Nextcloud instance. The module works by authenticating to the Nextcloud web interface, creating a malicious workflow that executes arbitrary system commands, and then triggering this workflow by uploading a file. The exploit supports customizable command payloads, including reverse shells, and includes cleanup routines to remove traces of exploitation. The code leverages standard Metasploit libraries for HTTP communication and session management. The main endpoints targeted are various Nextcloud API and WebDAV paths. The module is weaponized, as it is part of the Metasploit framework and supports flexible payload delivery.
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3 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.
No news coverage yet. Advisories and community discussion only.
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YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.