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.

Published : 2017-12-07 16:29 Updated : 2019-10-03 00:03

CVSS Score More info
Score 4.3 / 10
Vendor Product Version URI
Openssl Openssl 1.0.2b cpe:/a:openssl:openssl:1.0.2b
Openssl Openssl 1.0.2c cpe:/a:openssl:openssl:1.0.2c
Openssl Openssl 1.0.2d cpe:/a:openssl:openssl:1.0.2d
Openssl Openssl 1.0.2e cpe:/a:openssl:openssl:1.0.2e
Openssl Openssl 1.0.2f cpe:/a:openssl:openssl:1.0.2f
Openssl Openssl 1.0.2g cpe:/a:openssl:openssl:1.0.2g
Openssl Openssl 1.0.2h cpe:/a:openssl:openssl:1.0.2h
Openssl Openssl 1.0.2i cpe:/a:openssl:openssl:1.0.2i
Openssl Openssl 1.0.2j cpe:/a:openssl:openssl:1.0.2j
Openssl Openssl 1.0.2k cpe:/a:openssl:openssl:1.0.2k
Openssl Openssl 1.0.2l cpe:/a:openssl:openssl:1.0.2l
Openssl Openssl 1.0.2m cpe:/a:openssl:openssl:1.0.2m
Debian Debian Linux 9.0 cpe:/o:debian:debian_linux:9.0
  1. Openssl (1) Search CVE
    1. Openssl (12) Search CVE
      1. 1.0.2b
      2. 1.0.2c
      3. 1.0.2d
      4. 1.0.2e
      5. 1.0.2f
      6. 1.0.2g
      7. 1.0.2h
      8. 1.0.2i
      9. 1.0.2j
      10. 1.0.2k
      11. 1.0.2l
      12. 1.0.2m
  2. Debian (1) Search CVE
    1. Debian Linux (1) Search CVE
      1. 9.0


ID Name Description Links
CWE-125 Out-of-bounds Read The software reads data past the end, or before the beginning, of the intended buffer. CVE
CWE-787 Out-of-bounds Write The software writes data past the end, or before the beginning, of the intended buffer. CVE

History of changes

Date Event
2019-10-03 00:03
2018-08-09 01:29
2018-07-19 01:29
2018-07-14 01:29
2018-04-21 01:29
2018-04-20 01:29
2018-04-12 01:29
2018-01-24 02:29
2018-01-18 18:18
2018-01-18 02:29
2017-12-22 19:40
2017-12-19 02:29
2017-12-16 02:29
2017-12-14 02:29
2017-12-11 02:29
2017-12-10 02:29
2017-12-09 02:29
2017-12-07 16:29