Vulnerability identifier: #VU3403

Vulnerability risk: Medium

CVSSv3.1: 5.2 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2015-7940

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
The Bouncy Castle Crypto Package For Java
Universal components / Libraries / Libraries used by multiple products

Vendor: Legion of the Bouncy Castle Inc.

Description

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

The vulnerability exists due Bouncy Castle Java library before 1.51 does not validate a point is withing the elliptic curve, which makes it easier for remote attackers to obtain private keys via a series of crafted elliptic curve Diffie Hellman (ECDH) key exchanges, aka an "invalid curve attack."

Mitigation
Install update from vendor's website.

Vulnerable software versions

The Bouncy Castle Crypto Package For Java: 1.0 - 1.50

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External links
http://lists.fedoraproject.org/pipermail/package-announce/2016-January/174915.html
http://web-in-security.blogspot.ca/2015/09/practical-invalid-curve-attacks.html
http://www.debian.org/security/2015/dsa-3417
http://www.openwall.com/lists/oss-security/2015/10/22/7
http://www.openwall.com/lists/oss-security/2015/10/22/9

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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.