USN-4008-2: AppArmor update

5 June 2019

apparmor update

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

  • Ubuntu 16.04 LTS

Summary

Several policy updates were made for running under the recently updated Linux kernel.

Software Description

  • apparmor - Linux security system

Details

USN-4008-1 fixed multiple security issues in the Linux kernel. This update provides the corresponding changes to AppArmor policy for correctly operating under the Linux kernel with fixes for CVE-2019-11190. Without these changes, some profile transitions may be unintentionally denied due to missing mmap (’m’) rules.

Original advisory details:

Robert Święcki discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid elf binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid elf binary. (CVE-2019-11190)

It was discovered that a null pointer dereference vulnerability existed in the LSI Logic MegaRAID driver in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2019-11810)

It was discovered that a race condition leading to a use-after-free existed in the Reliable Datagram Sockets (RDS) protocol implementation in the Linux kernel. The RDS protocol is blacklisted by default in Ubuntu. If enabled, a local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-11815)

Federico Manuel Bento discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid a.out binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid a.out binary. (CVE-2019-11191)

As a hardening measure, this update disables a.out support.

Update instructions

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

Ubuntu 16.04 LTS
apparmor-profiles - 2.10.95-0ubuntu2.11
python3-apparmor - 2.10.95-0ubuntu2.11

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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

References