Joplin version 2.8.8 allows an external attacker to execute arbitrary commands remotely on any client that opens a link in a malicious markdown file, via Joplin. This is possible because the application does not properly validate the schema/protocol of existing links in the markdown file before passing them to the shell.openExternal function.

References

• https://nvd.nist.gov/vuln/detail/CVE-2022-40277
• https://fluidattacks.com/advisories/skrillex