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Ubuntu Security Notice USN-6663-1
February 27, 2024

openssl update

A security issue affects these releases of Ubuntu and its derivatives:

• Ubuntu 23.10
• Ubuntu 22.04 LTS
• Ubuntu 20.04 LTS
• Ubuntu 18.04 LTS (Available with Ubuntu Pro)

Summary:

Add implicit rejection in PKCS#1 v1.5 in OpenSSL.

Software Description:

• openssl: Secure Socket Layer (SSL) cryptographic library and tools

Details:

As a security improvement, this update prevents OpenSSL
from returning an error when detecting wrong padding
in PKCS#1 v1.5 RSA, to prevent its use in possible
Bleichenbacher timing attacks.

Update instructions:

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

Ubuntu 23.10:
libssl-doc 3.0.10-1ubuntu2.3
libssl3 3.0.10-1ubuntu2.3
openssl 3.0.10-1ubuntu2.3

Ubuntu 22.04 LTS:
libssl-doc 3.0.2-0ubuntu1.15
libssl3 3.0.2-0ubuntu1.15
openssl 3.0.2-0ubuntu1.15

Ubuntu 20.04 LTS:
libssl-doc 1.1.1f-1ubuntu2.22
libssl1.1 1.1.1f-1ubuntu2.22
openssl 1.1.1f-1ubuntu2.22

Ubuntu 18.04 LTS (Available with Ubuntu Pro):
libssl-doc 1.1.1-1ubuntu2.1~18.04.23+esm5
libssl1.1 1.1.1-1ubuntu2.1~18.04.23+esm5
openssl 1.1.1-1ubuntu2.1~18.04.23+esm5

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

References:
https://ubuntu.com/security/notices/USN-6663-1
https://launchpad.net/bugs/2054090

Package Information:
https://launchpad.net/ubuntu/+source/openssl/3.0.10-1ubuntu2.3
https://launchpad.net/ubuntu/+source/openssl/3.0.2-0ubuntu1.15
https://launchpad.net/ubuntu/+source/openssl/1.1.1f-1ubuntu2.22