Out-of-bounds Read Affecting openssl package, versions <1.0.2g-1ubuntu4.10


0.0
medium

Snyk CVSS

    Attack Complexity High
    Confidentiality High

    Threat Intelligence

    EPSS 94.55% (100th percentile)
Expand this section
NVD
5.9 medium
Expand this section
Red Hat
5.9 medium

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk ID SNYK-UBUNTU1604-OPENSSL-374519
  • published 7 Dec 2017
  • disclosed 7 Dec 2017

How to fix?

Upgrade Ubuntu:16.04 openssl to version 1.0.2g-1ubuntu4.10 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream openssl package and not the openssl package as distributed by Ubuntu. See How to fix? for Ubuntu:16.04 relevant fixed versions and status.

OpenSSL 1.0.2 (starting from version 1.0.2b) introduced an "error state" 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.