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MEDIUM

openssl: Read/write after SSL object in error state

Published Dec 7, 2017

Description

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.

Affected products

Remediation

No remediation recorded yet.

Metrics

Weaknesses (3)

CWE-125

Out-of-bounds Read

CWE-391

CWE-787

Out-of-bounds Write

References (25)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner openssl
Published Dec 7, 2017
Updated Sep 17, 2024
Reserved Dec 16, 2016
Link CVE-2017-3737
CISA Vulnrichment
Updated n/a
NVD
Status Modified
Modified Jun 17, 2026
Link CVE-2017-3737
Red Hat
Severity Moderate
Public date Dec 7, 2017
Links CVE-2017-3737 - Bugzilla