Read/write after SSL object in error state (CVE-2017-3737)

  • 7022626
  • 31-Jan-2018
  • 01-Jun-2018

Environment

Reflection Desktop 16.1 version 16.1.348 and earlier
InfoConnect Desktop 16.1 version 16.1.348 and earlier

Situation

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.

Resolution

This issue is addressed in Reflection/InfoConnect Desktop 16.1 version 16.1.362 and higher.

Status

Security Alert

Additional Information

For vulnerability details, see the National Vulnerability Database:

https://nvd.nist.gov/vuln/detail/CVE-2017-3737