CVE-2017-3737

CVE Details

Release Date:

2018-07-30

Description

OpenSSL 1.0.2 (starting from version 1.0.2b) introduced an errorstate mechanism. The intent was that if a fatal error occurred during a handshake then OpenSSL would move into the error state and would immediately fail if you attempted to continue the handshake. This works as designed for the explicit handshake functions (SSL_do_handshake(), SSL_accept() and SSL_connect()), however due to a bug it does not work correctly if SSL_read() or SSL_write() is called directly. In that scenario, if the handshake fails then a fatal error will be returned in the initial function call. If SSL_read()/SSL_write() is subsequently called by the application for the same SSL object then it will succeed and the data is passed without being decrypted/encrypted directly from the SSL/TLS record layer. In order to exploit this issue an application bug would have to be present that resulted in a call to SSL_read()/SSL_write() being issued after having already received a fatal error. OpenSSL version 1.0.2b-1.0.2m are affected. Fixed in OpenSSL 1.0.2n. OpenSSL 1.1.0 is not affected.

See more information about CVE-2017-3737 from MITRE CVE dictionary and NIST NVD

CVSS v2.0 metrics

NOTE: The following CVSS v2.0 metrics and score provided are preliminary and subject to review.

Base Score:	4.3	Base Metrics:	AV:N/AC:M/Au:N/C:P/I:N/A:N
Access Vector:	Network	Attack Complexity:	Medium
Authentication:	None required	Confidentiality Impact:	Partial
Integrity Impact:	None	Availability Impact:	None

Errata information

Platform	Errata	Release Date
Oracle Linux version 7 (openssl)	ELSA-2018-0998	2018-04-16

This page is generated automatically and has not been checked for errors or omissions. For clarification or corrections please contact the Oracle Linux ULN team