CVE-2025-66480: Wildfire has Arbitrary File Upload via Directory Traversal in UploadFileAction

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-02 · updated 2026-06-17
Weakness: CWE-22

Description

Wildfire IM is an instant messaging and real-time audio/video solution. Prior to 1.4.3, a critical vulnerability exists in the im-server component related to the file upload functionality found in com.xiaoleilu.loServer.action.UploadFileAction. The application exposes an endpoint (/fs) that handles multipart file uploads but fails to properly sanitize the filename provided by the user. Specifically, the writeFileUploadData method directly concatenates the configured storage directory with the filename extracted from the upload request without stripping directory traversal sequences (e.g., ../../). This vulnerability allows an attacker to write arbitrary files to any location on the server's filesystem where the application process has write permissions. By uploading malicious files (such as scripts, executables, or overwriting configuration files like authorized_keys or cron jobs), an attacker can achieve Remote Code Execution (RCE) and completely compromise the server. This vulnerability is fixed in 1.4.3.

Affected products

wildfirechat im-server: before 1.4.3 — fixed in 1.4.3

How to fix

Upgrade to a fixed version: wildfirechat im-server 1.4.3. Check the vendor advisory for mitigations.

References

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