Vulnerability identifier: #VU40173

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2015-5738

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
FortiOS
Operating systems & Components / Operating system

Vendor: Fortinet, Inc

Description

The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.

The RSA-CRT implementation in the Cavium Software Development Kit (SDK) 2.x, when used on OCTEON II CN6xxx Hardware on Linux to support TLS with Perfect Forward Secrecy (PFS), makes it easier for remote attackers to obtain private RSA keys by conducting a Lenstra side-channel attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

FortiOS: 5.0.12, 5.2.5, 5.4.0

---

External links
http://fortiguard.com/advisory/rsa-crt-key-leak-under-certain-conditions
http://people.redhat.com/~fweimer/rsa-crt-leaks.pdf
http://support.f5.com/kb/en-us/solutions/public/k/91/sol91245485.html

---

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.