=========================================================================Ubuntu Security Notice USN-4989-1
June 16, 2021

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

- Ubuntu 21.04
- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in BlueZ.

Software Description:
- bluez: Bluetooth tools and daemons

Details:

It was discovered that BlueZ incorrectly checked certain permissions when
pairing. A local attacker could possibly use this issue to impersonate
devices. (CVE-2020-26558)

Jay LV discovered that BlueZ incorrectly handled redundant disconnect MGMT
events. A local attacker could use this issue to cause BlueZ to crash,
resulting in a denial of service, or possibly execute arbitrary code. This
issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2020-27153)

Ziming Zhang discovered that BlueZ incorrectly handled certain array
indexes. A local attacker could use this issue to cause BlueZ to crash,
resulting in a denial of service, or possibly obtain sensitive information.
This issue only affected Ubuntu 20.04 LTS and Ubuntu 20.10. (CVE-2021-3588)

Update instructions:

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

Ubuntu 21.04:
  bluez                           5.56-0ubuntu4.1
  libbluetooth3                   5.56-0ubuntu4.1

Ubuntu 20.10:
  bluez                           5.55-0ubuntu1.2
  libbluetooth3                   5.55-0ubuntu1.2

Ubuntu 20.04 LTS:
  bluez                           5.53-0ubuntu3.2
  libbluetooth3                   5.53-0ubuntu3.2

Ubuntu 18.04 LTS:
  bluez                           5.48-0ubuntu3.5
  libbluetooth3                   5.48-0ubuntu3.5

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-4989-1
  CVE-2020-26558, CVE-2020-27153, CVE-2021-3588

Package Information:
  https://launchpad.net/ubuntu/+source/bluez/5.56-0ubuntu4.1
  https://launchpad.net/ubuntu/+source/bluez/5.55-0ubuntu1.2
  https://launchpad.net/ubuntu/+source/bluez/5.53-0ubuntu3.2
  https://launchpad.net/ubuntu/+source/bluez/5.48-0ubuntu3.5