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).
https://www.openssl.org/news/secadv/20190226.txt
https://usn.ubuntu.com/3899-1/
http://www.securityfocus.com/bid/107174
https://www.debian.org/security/2019/dsa-4400
https://lists.debian.org/debian-lts-announce/2019/03/msg00003.html
https://security.netapp.com/advisory/ntap-20190301-0002/
https://security.netapp.com/advisory/ntap-20190301-0001/
https://security.gentoo.org/glsa/201903-10
https://support.f5.com/csp/article/K18549143
https://www.tenable.com/security/tns-2019-02
http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00041.html
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00019.html
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00047.html
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00046.html
https://security.netapp.com/advisory/ntap-20190423-0002/
https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html
https://www.tenable.com/security/tns-2019-03
https://kc.mcafee.com/corporate/index?page=content&id=SB10282
http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00049.html
http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00080.html
https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html
https://access.redhat.com/errata/RHSA-2019:2304
https://access.redhat.com/errata/RHSA-2019:2437
https://access.redhat.com/errata/RHSA-2019:2439
https://access.redhat.com/errata/RHSA-2019:2471
https://support.f5.com/csp/article/K18549143?utm_source=f5support&utm_medium=RSS
https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
https://access.redhat.com/errata/RHSA-2019:3929
https://access.redhat.com/errata/RHSA-2019:3931
https://www.oracle.com/security-alerts/cpujan2020.html
Source: MITRE
Published: 2019-02-27
Updated: 2022-08-19
Type: CWE-203
Base Score: 4.3
Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N
Impact Score: 2.9
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 5.9
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Impact Score: 3.6
Exploitability Score: 2.2
Severity: MEDIUM