CVE-2018-12395 : What You Need to Know
Learn about CVE-2018-12395, a WebExtension vulnerability in Firefox ESR and Firefox versions allowing bypassing domain restrictions through header rewriting. Find out the impacted systems, exploitation mechanism, and mitigation steps.
A WebExtension vulnerability in Firefox ESR and Firefox versions allows bypassing domain restrictions through header rewriting.
Understanding CVE-2018-12395
This CVE involves a technique known as domain fronting that impacts Firefox ESR versions prior to 60.3 and Firefox versions prior to 63.
What is CVE-2018-12395?
- A WebExtension vulnerability enables bypassing domain restrictions by modifying Host request headers using the webRequest API.
- This technique, called domain fronting, allows access to restricted domains associated with the same host.
The Impact of CVE-2018-12395
- Affected versions include Firefox ESR < 60.3 and Firefox < 63.
Technical Details of CVE-2018-12395
Vulnerability Description
- By rewriting Host request headers, a WebExtension can bypass domain restrictions through domain fronting.
Affected Systems and Versions
- Products: Firefox ESR, Firefox
- Vendor: Mozilla
- Versions: Firefox ESR < 60.3, Firefox < 63
Exploitation Mechanism
- WebExtension bypasses domain restrictions by modifying Host request headers using the webRequest API.
Mitigation and Prevention
Immediate Steps to Take
- Update Firefox ESR to version 60.3 or higher.
- Update Firefox to version 63 or higher.
Long-Term Security Practices
- Regularly update browsers to the latest versions.
- Educate users on safe browsing practices.
Patching and Updates
- Apply security patches promptly to mitigate vulnerabilities.