[USN-4504-1] OpenSSL vulnerabilities

 ---------- Forwarded message ---------

From: Marc Deslauriers <marc.deslauriers@canonical.com>

Date: Sep 16, 2020 11:09PM

Robert Merget, Marcus Brinkmann, Nimrod Aviram, and Juraj Somorovsky

discovered that certain Diffie-Hellman ciphersuites in the TLS

specification and implemented by OpenSSL contained a flaw. A remote

attacker could possibly use this issue to eavesdrop on encrypted

communications. This was fixed in this update by removing the insecure

ciphersuites from OpenSSL. (CVE-2020-1968)

Cesar Pereida García, Sohaib ul Hassan, Nicola Tuveri, Iaroslav Gridin,

Alejandro Cabrera Aldaya, and Billy Brumley discovered that OpenSSL

incorrectly handled ECDSA signatures. An attacker could possibly use this

issue to perform a timing side-channel attack and recover private ECDSA

keys. This issue only affected Ubuntu 18.04 LTS. (CVE-2019-1547)

Guido Vranken discovered that OpenSSL incorrectly performed the x86_64

Montgomery squaring procedure. While unlikely, a remote attacker could

possibly use this issue to recover private keys. This issue only affected

Ubuntu 18.04 LTS. (CVE-2019-1551)

Bernd Edlinger discovered that OpenSSL incorrectly handled certain

decryption functions. In certain scenarios, a remote attacker could

possibly use this issue to perform a padding oracle attack and decrypt

traffic. This issue only affected Ubuntu 18.04 LTS. (CVE-2019-1563)

References:

  https://usn.ubuntu.com/4504-1

  CVE-2019-1547, CVE-2019-1551, CVE-2019-1563, CVE-2020-1968