Vulnerability identifier: #VU9870

Vulnerability risk: Medium

CVSSv3.1: 4.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N/E:P/RL:O/RC:C]

CVE-ID: N/A

CWE-ID: CWE-385

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers
Firefox ESR
Client/Desktop applications / Web browsers

Vendor: Mozilla

Description
The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to an error in Intel processor microcode, which can lead to timing side-channel attack and data extraction from modern CPUs.

The vulnerability is dubbed "Spectre". The PoC-code was created in JavaScript, which demonstrated possibility of the attack.

Mitigation
Update to version 57.0.4.

Vulnerable software versions

Mozilla Firefox: 40.0 - 57.0.3

Firefox ESR: 45.0 - 45.8

---

External links
http://www.mozilla.org/en-US/security/advisories/mfsa2018-01/

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.