Horizon Alert
Summary of the vulnerability and why it matters
This vulnerability in Gotenberg allows an unauthenticated attacker to manipulate files on the server. By sending specially crafted metadata, an attacker can trick the system into renaming, moving, or overwriting any PDF file. This could lead to significant disruption and data integrity issues.
- Attacker can overwrite critical files.
- Attacker can move files to any location.
- Can impact any PDF being processed.
Attack Path
How an attacker could exploit the issue
An unauthenticated attacker can exploit Gotenberg's metadata write endpoint by inserting a newline character into a metadata value. This bypasses input sanitization, allowing the attacker to inject malicious ExifTool commands to manipulate files within the container. They can rename or move PDFs to arbitrary locations, overwrite existing files, or create symbolic and hard links.
- Targets metadata write endpoint.
- Unauthenticated network access needed.
- Exploits unsanitized metadata values.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability in Gotenberg allows unauthenticated attackers to manipulate PDF metadata, potentially renaming files, moving them to arbitrary locations, overwriting files, or creating symbolic and hard links. The exploit bypasses a previous fix, indicating a persistent issue that attackers might find appealing due to the broad impact on file system operations.
- Exploitation of unpatched Gotenberg is probable.
- Public exploit code is not yet confirmed.
- The vulnerability impacts file operations within the container.
Priority actions
Operational Fix
Recommended remediation, mitigation, and detection steps
Teams should prioritize blocking or isolating Gotenberg instances due to critical, exploitable vulnerabilities. The vulnerability allows unauthenticated attackers to rename, move, or overwrite files within the container filesystem by injecting arbitrary ExifTool pseudo-tags.
- Isolate or take affected Gotenberg services offline.
- Block network traffic to vulnerable instances.
- Upgrade Gotenberg to version 8.31.0 or later.
