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Security Advisory

USN-4376-1: OpenSSL vulnerabilities

USN-4376-1: OpenSSL vulnerabilities




Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 16.04
  • Canonical Ubuntu 18.04


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. (CVE-2019-1547)

Matt Caswell discovered that OpenSSL incorrectly handled the random number generator (RNG). This may result in applications that use the fork() system call sharing the same RNG state between the parent and the child, contrary to expectations. This issue only affected Ubuntu 18.04 LTS and Ubuntu 19.10. (CVE-2019-1549)

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. (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. (CVE-2019-1563)

CVEs contained in this USN include: CVE-2019-1547, CVE-2019-1549, CVE-2019-1551, CVE-2019-1563.

Affected Cloud Foundry Products and Versions

Severity is low unless otherwise noted.

  • cflinuxfs3
    • All versions prior to 0.189.0
  • Xenial Stemcells
    • 170.x versions prior to 170.221
    • 250.x versions prior to 250.200
    • 315.x versions prior to 315.185
    • 456.x versions prior to 456.114
    • 621.x versions prior to 621.76
    • All other stemcells not listed.
  • CF Deployment
    • All versions prior to v13.5.0


Users of affected products are strongly encouraged to follow the mitigations below. The Cloud Foundry project recommends upgrading the following releases:

  • cflinuxfs3
    • Upgrade All versions to 0.189.0 or greater
  • Xenial Stemcells
    • Upgrade 170.x versions to 170.221 or greater
    • Upgrade 250.x versions to 250.200 or greater
    • Upgrade 315.x versions to 315.185 or greater
    • Upgrade 456.x versions to 456.114 or greater
    • Upgrade 621.x versions to 621.76 or greater
    • All other stemcells should be upgraded to the latest version available on
  • CF Deployment
    • Upgrade All versions to v13.5.0 or greater


2020-05-28: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR