A Cyrus SASL security update has been released for Ubuntu Linux 19.10, 18.04 LTS, 16.04 LTS, 14.04 ESM, and 12.04 ESM.

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Ubuntu Security Notice USN-4256-1
January 28, 2020

cyrus-sasl2 vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 19.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM
- Ubuntu 12.04 ESM

Summary:

Cyrus SASL could be made to crash or execute arbitrary code if it received
a specially crafted LDAP packet.

Software Description:
- cyrus-sasl2: Cyrus Simple Authentication and Security Layer

Details:

It was discovered that Cyrus SASL incorrectly handled certain LDAP packets.
An attacker could possibly use this issue to execute arbitrary code or cause
a denial of service.

Update instructions:

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

Ubuntu 19.10:
libsasl2-2 2.1.27+dfsg-1ubuntu0.1

Ubuntu 18.04 LTS:
libsasl2-2 2.1.27~101-g0780600+dfsg-3ubuntu2.1

Ubuntu 16.04 LTS:
libsasl2-2 2.1.26.dfsg1-14ubuntu0.2

Ubuntu 14.04 ESM:
libsasl2-2 2.1.25.dfsg1-17ubuntu0.1~esm1

Ubuntu 12.04 ESM:
libsasl2-2 2.1.25.dfsg1-3ubuntu0.2

After a standard system update you need to restart services using
SASL to effect the necessary changes.

References:
https://usn.ubuntu.com/4256-1
CVE-2019-19906

Package Information:
https://launchpad.net/ubuntu/+source/cyrus-sasl2/2.1.27+dfsg-1ubuntu0.1
https://launchpad.net/ubuntu/+source/cyrus-sasl2/2.1.27~101-g0780600+dfsg-3ubuntu2.1
https://launchpad.net/ubuntu/+source/cyrus-sasl2/2.1.26.dfsg1-14ubuntu0.2