USN-4738-1: OpenSSL vulnerabilities

18 February 2021

Several security issues were fixed in OpenSSL.

Releases

Packages

  • openssl - Secure Socket Layer (SSL) cryptographic library and tools
  • openssl1.0 - Secure Socket Layer (SSL) cryptographic library and tools

Details

Paul Kehrer discovered that OpenSSL incorrectly handled certain input
lengths in EVP functions. A remote attacker could possibly use this issue
to cause OpenSSL to crash, resulting in a denial of service.
(CVE-2021-23840)

Tavis Ormandy discovered that OpenSSL incorrectly handled parsing issuer
fields. A remote attacker could possibly use this issue to cause OpenSSL to
crash, resulting in a denial of service. (CVE-2021-23841)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 20.10
Ubuntu 20.04
Ubuntu 18.04
Ubuntu 16.04

After a standard system update you need to reboot your computer to make
all the necessary changes.

Related notices

  • USN-5088-1: qemu-efi-arm, ovmf-ia32, qemu-efi-aarch64, edk2, qemu-efi, ovmf
  • USN-4745-1: libssl-doc, openssl, libssl1.0.0-udeb, libcrypto1.0.0-udeb, libssl1.0.0, libssl-dev