|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).|
|Source||CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)|
|NVD severity||medium (attack range: remote)|
Vulnerable and fixed packages
The table below lists information on source packages.
|stretch (security), stretch||1.1.0k-1~deb9u1||fixed|
|openssl1.0 (PTS)||stretch (security), stretch||1.0.2s-1~deb9u1||fixed|
The information below is based on the following data on fixed versions.
OpenSSL_1_1_0-stable: https://git.openssl.org/?p=openssl.git;a=commit;h=5741d5bb74797e4532acc9f42e54c44a2726c179 (only hardening)
1.1.0 is not impacted by CVE-2019-1559. The CVE is a result of applications
calling SSL_shutdown after a fatal alert has occurred. 1.1.0 is not vulnerable
to this issue, marking first 1.1 upload of src:openssl as fixed