#VU9594 Improper input validation in OpenSSL - CVE-2017-3737

Vulnerability identifier: #VU9594

Vulnerability risk: Medium

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

CVE-ID: CVE-2017-3737

CWE-ID: CWE-20

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 gain access to potentially sensitive information on the target system.

The weakness exists due to an "error state mechanism" when SSL_read() or SSL_write() is called directly after SSL object. A remote attacker can a specially crafted input, trigger a fatal error during a handshake and return it in the initial function call to access or modify sensitive information.

Mitigation
Update to version 1.0.2n.

Vulnerable software versions

OpenSSL: 1.0.2m - 1.0.2

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External links
https://www.openssl.org/news/secadv/20171207.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.