#VU2765 Information disclosure in OpenSSL - CVE-2015-3193

Vulnerability identifier: #VU2765

Vulnerability risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2015-3193

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OpenSSL
Server applications / Encryption software

Vendor: OpenSSL Software Foundation

Description
The vulnerability allows a remote attacker to obtain potentially sensitive information on the target system.

The weakness exists in the Montgomery squaring implementation in crypto/bn/asm/x86_64-mont5.pl on the x86_64 platform, as used by the BN_mod_exp function, due to mishandling of carry propagation and producing incorrect output. A remote attacker can gain potentially sensitive private-key information via an attack against use of a (1) Diffie-Hellman (DH) or (2) Diffie-Hellman Ephemeral (DHE) ciphersuite.

Mitigation
Update to version 1.0.2e.

Vulnerable software versions

OpenSSL: 1.0.2d - 1.0.2

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External links
https://www.openssl.org/news/secadv/20151203.txt

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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.