CVE-2024-51998
changedetection.io path traversal using file URI scheme without supplying hostname
Description
### Summary The validation for the file URI scheme falls short, and results in an attacker being able to read any file on the system. This issue only affects instances with a webdriver enabled, and `ALLOW_FILE_URI` false or not defined. ### Details The check used for URL protocol, `is_safe_url`, allows `file:` as a URL scheme: https://github.com/dgtlmoon/changedetection.io/blob/e0abf0b50507a8a3d0c1d8522ab23519b3e4cdf4/changedetectionio/model/Watch.py#L11-L13 It later checks if local files are permitted, but one of the preconditions for the check is that the URL starts with `file://`. The issue comes with the fact that the file URI scheme is not required to have double slashes. > A valid file URI must therefore begin with either `file:/path` (no hostname), `file:///path` (empty hostname), or `file://hostname/path`. > — [Wikipedia](https://en.wikipedia.org/wiki/File_URI_scheme#Number_of_slash_characters) https://github.com/dgtlmoon/changedetection.io/blob/e0abf0b50507a8a3d0c1d8522ab23519b3e4cdf4/changedetectionio/processors/__init__.py#L37-L41 ### PoC 1. Open up a changedetection.io instance with a webdriver configured 2. Create a new watch: `file:/etc/passwd` or a similar path for your operating system. Enable webdriver mode 3. Wait for it to be checked 4. Open preview 5. Notice contents of the file
How to fix CVE-2024-51998
To remediate CVE-2024-51998, upgrade the affected package to a fixed version below.
- —upgrade to 0.47.6 or later
Is CVE-2024-51998 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 0.47.6