Vulnerability identifier: #VU1914

Vulnerability risk: Medium

CVSSv3.1: 6.9 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C]

CVE-ID: CVE-2016-0800

CWE-ID: CWE-327

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
OpenSSL
Server applications / Encryption software

Vendor: OpenSSL Software Foundation

Description
The vulnerability allows a remote attacker to decrypt sensitive information.

The vulnerability exists due to usage of weak SSLv2 protocol, which requires to send a ServerVerify message before establishing that a client possesses certain plaintext RSA data. A remote attacker can decrypt TLS ciphertext data by leveraging a Bleichenbacher RSA padding oracle.

The vulnerability is dubbed "DROWN" attack.

Mitigation
Update to version 1.0.1s or 1.0.2g.

Vulnerable software versions

OpenSSL: 1.0.2, 1.0.1 - 1.0.1l, 1.0.0 - 1.0.0r, 0.9.8 - 0.9.8ze

---

External links
http://drownattack.com/drown-attack-paper.pdf
http://openssl.org/news/secadv/20160301.txt

---

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, a fully functional exploit for this vulnerability is available.