1. Ubuntu Security Notices
  2. USN-4185-2

USN-4185-2: Linux kernel (Azure) vulnerabilities

Publication date

13 November 2019

Overview

Several security issues were fixed in the Linux kernel.

Releases

Packages

  • linux-azure - Linux kernel for Microsoft Azure Cloud systems

Details

Stephan van Schaik, Alyssa Milburn, Sebastian Österlund, Pietro Frigo,
Kaveh Razavi, Herbert Bos, Cristiano Giuffrida, Giorgi Maisuradze, Moritz
Lipp, Michael Schwarz, Daniel Gruss, and Jo Van Bulck discovered that Intel
processors using Transactional Synchronization Extensions (TSX) could
expose memory contents previously stored in microarchitectural buffers to a
malicious process that is executing on the same CPU core. A local attacker
could use this to expose sensitive information. (CVE-2019-11135)

Deepak Gupta discovered that on certain Intel processors, the Linux kernel
did not properly perform invalidation on page table updates by virtual
guest operating systems. A local attacker in a guest VM could use this to
cause a denial of service (host system crash). (CVE-2018-12207)

Ori Nimron discovered that the AX25 network protocol implementation in...

Stephan van Schaik, Alyssa Milburn, Sebastian Österlund, Pietro Frigo,
Kaveh Razavi, Herbert Bos, Cristiano Giuffrida, Giorgi Maisuradze, Moritz
Lipp, Michael Schwarz, Daniel Gruss, and Jo Van Bulck discovered that Intel
processors using Transactional Synchronization Extensions (TSX) could
expose memory contents previously stored in microarchitectural buffers to a
malicious process that is executing on the same CPU core. A local attacker
could use this to expose sensitive information. (CVE-2019-11135)

Deepak Gupta discovered that on certain Intel processors, the Linux kernel
did not properly perform invalidation on page table updates by virtual
guest operating systems. A local attacker in a guest VM could use this to
cause a denial of service (host system crash). (CVE-2018-12207)

Ori Nimron discovered that the AX25 network protocol implementation in the
Linux kernel did not properly perform permissions checks. A local attacker
could use this to create a raw socket. (CVE-2019-17052)

Ori Nimron discovered that the IEEE 802.15.4 Low-Rate Wireless network
protocol implementation in the Linux kernel did not properly perform
permissions checks. A local attacker could use this to create a raw socket.
(CVE-2019-17053)

Ori Nimron discovered that the Appletalk network protocol implementation in
the Linux kernel did not properly perform permissions checks. A local
attacker could use this to create a raw socket. (CVE-2019-17054)

Ori Nimron discovered that the modular ISDN network protocol implementation
in the Linux kernel did not properly perform permissions checks. A local
attacker could use this to create a raw socket. (CVE-2019-17055)

Ori Nimron discovered that the Near field Communication (NFC) network
protocol implementation in the Linux kernel did not properly perform
permissions checks. A local attacker could use this to create a raw socket.
(CVE-2019-17056)

Update instructions

Please note that mitigating the TSX (CVE-2019-11135) issue requires a corresponding Intel processor microcode update. After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well.

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

Ubuntu Release Package Version
14.04 trusty linux-image-azure –  4.15.0.1063.49
linux-image-4.15.0-1063-azure –  4.15.0-1063.68~14.04.1

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References

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