Anki launches a local HTTP server to serve media files and web pages for parts of its interface. While the server has a CORS setup, requests from other origins were not blocked, allowing malicious websites to potentially trigger side-effecting requests.
// browser impactThe severity varies by browser because of Private Network Access (PNA), a newer spec that restricts web pages from making requests to localhost/local network addresses:
Chrome/Chromium (including Edge, Brave): Largely protected, as Chrome has implemented PNA restrictions for several years and now puts local network access behind a permission prompt. Safari: Hasn't implemented PNA yet, though macOS has some OS-level protections. Firefox: Most vulnerable — hasn't implemented PNA yet, though it's reportedly planned for Firefox 151.
// patchesThe issue was fixed as of Anki 25.09.3
// referencesCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- Present
- Privileges required
- None
- User interaction
- Active
- Confidentiality (vulnerable system)
- Low
- Integrity (vulnerable system)
- Low
- Availability (vulnerable system)
- Low
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None