Select your cookie preferences

We use cookies and similar tools to enhance your experience, provide our services, deliver relevant advertising, and make improvements. Approved third parties also use these tools to help us deliver advertising and provide certain site features.

CVE-2019-1559

Public on 2019-02-27
Modified on 2019-11-14
Description

If an application encounters a fatal protocol error and then calls SSL_shutdown() twice (once to send a close_notify, and once to receive one) then OpenSSL can respond differently to the calling application if a 0 byte record is received with invalid padding compared to if a 0 byte record is received with an invalid MAC. If the application then behaves differently based on that in a way that is detectable to the remote peer, then this amounts to a padding oracle that could be used to decrypt data. In order for this to be exploitable "non-stitched" ciphersuites must be in use. Stitched ciphersuites are optimised implementations of certain commonly used ciphersuites. Also the application must call SSL_shutdown() twice even if a protocol error has occurred (applications should not do this but some do anyway). Fixed in OpenSSL 1.0.2r (Affected 1.0.2-1.0.2q).

Severity
Medium
See what this means
CVSS v3 Base Score
5.9
See breakdown
Continue reading

Affected Packages

Platform Package Release Date Advisory
Amazon Linux 1 openssl 2019-04-04 19:13 ALAS-2019-1188
Amazon Linux 2 - Core openssl 2019-04-04 21:45 ALAS2-2019-1188
Amazon Linux 2 - Core openssl 2019-11-11 17:41 ALAS2-2019-1362

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD CVSSv2 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N
NVD CVSSv3 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N