Sendbox bypass in Mozilla Firefox and Firefox ESR - CVE-2017-5454

Detailed vulnerability description

The vulnerability allows a remote attacker to read files from local filesystem.

The vulnerability exists due to an error in sendbox implementation. A remote attacker can use the file picker to access different files than those selected in the file picker through the use of relative paths.

Successful exploitation of the vulnerability may allow an attacker to read arbitrary files from the vulnerable system.

How to mitigate CVE-2017-5454

Sources

• https://www.mozilla.org/en-US/security/advisories/mfsa2017-10/
• https://www.mozilla.org/en-US/security/advisories/mfsa2017-12/