CVE Vulnerabilities

CVE-2019-13233

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Published: Jul 04, 2019 | Modified: Jul 20, 2019
CVSS 3.x
7
HIGH
Source:
NVD
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
4.4 MEDIUM
AV:L/AC:M/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
5.1 MODERATE
CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Ubuntu

In arch/x86/lib/insn-eval.c in the Linux kernel before 5.1.9, there is a use-after-free for access to an LDT entry because of a race condition between modify_ldt() and a #BR exception for an MPX bounds violation.

Weakness

The program contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.

Affected Software

Name Vendor Start Version End Version
Linux_kernel Linux * *
Red Hat Enterprise Linux 7 RedHat kernel-rt-0:3.10.0-1127.rt56.1093.el7 *
Red Hat Enterprise Linux 7 RedHat kernel-0:3.10.0-1127.el7 *
Red Hat Enterprise Linux 7.6 Extended Update Support RedHat kernel-0:3.10.0-957.56.1.el7 *
Red Hat Enterprise Linux 7.7 Extended Update Support RedHat kernel-0:3.10.0-1062.26.1.el7 *
Red Hat Enterprise Linux 8 RedHat kernel-rt-0:4.18.0-147.rt24.93.el8 *
Red Hat Enterprise Linux 8 RedHat kernel-0:4.18.0-147.el8 *
Linux Ubuntu bionic *
Linux Ubuntu cosmic *
Linux Ubuntu disco *
Linux Ubuntu precise/esm *
Linux Ubuntu trusty *
Linux Ubuntu trusty/esm *
Linux Ubuntu upstream *
Linux-aws Ubuntu bionic *
Linux-aws Ubuntu cosmic *
Linux-aws Ubuntu disco *
Linux-aws Ubuntu trusty *
Linux-aws Ubuntu trusty/esm *
Linux-aws Ubuntu upstream *
Linux-aws-5.0 Ubuntu upstream *
Linux-aws-hwe Ubuntu esm-infra/xenial *
Linux-aws-hwe Ubuntu upstream *
Linux-aws-hwe Ubuntu xenial *
Linux-azure Ubuntu bionic *
Linux-azure Ubuntu cosmic *
Linux-azure Ubuntu disco *
Linux-azure Ubuntu esm-infra/xenial *
Linux-azure Ubuntu trusty *
Linux-azure Ubuntu trusty/esm *
Linux-azure Ubuntu upstream *
Linux-azure Ubuntu xenial *
Linux-azure-5.3 Ubuntu upstream *
Linux-azure-edge Ubuntu bionic *
Linux-azure-edge Ubuntu upstream *
Linux-azure-edge Ubuntu xenial *
Linux-euclid Ubuntu upstream *
Linux-euclid Ubuntu xenial *
Linux-flo Ubuntu trusty *
Linux-flo Ubuntu upstream *
Linux-flo Ubuntu xenial *
Linux-gcp Ubuntu bionic *
Linux-gcp Ubuntu cosmic *
Linux-gcp Ubuntu disco *
Linux-gcp Ubuntu esm-infra/xenial *
Linux-gcp Ubuntu upstream *
Linux-gcp Ubuntu xenial *
Linux-gcp-5.3 Ubuntu upstream *
Linux-gcp-edge Ubuntu bionic *
Linux-gcp-edge Ubuntu upstream *
Linux-gke Ubuntu upstream *
Linux-gke Ubuntu xenial *
Linux-gke-4.15 Ubuntu bionic *
Linux-gke-4.15 Ubuntu upstream *
Linux-gke-5.0 Ubuntu upstream *
Linux-goldfish Ubuntu trusty *
Linux-goldfish Ubuntu upstream *
Linux-goldfish Ubuntu xenial *
Linux-grouper Ubuntu trusty *
Linux-grouper Ubuntu upstream *
Linux-hwe Ubuntu bionic *
Linux-hwe Ubuntu esm-infra/xenial *
Linux-hwe Ubuntu upstream *
Linux-hwe Ubuntu xenial *
Linux-hwe-edge Ubuntu bionic *
Linux-hwe-edge Ubuntu esm-infra/xenial *
Linux-hwe-edge Ubuntu upstream *
Linux-hwe-edge Ubuntu xenial *
Linux-kvm Ubuntu bionic *
Linux-kvm Ubuntu cosmic *
Linux-kvm Ubuntu disco *
Linux-kvm Ubuntu upstream *
Linux-lts-trusty Ubuntu precise/esm *
Linux-lts-trusty Ubuntu upstream *
Linux-lts-utopic Ubuntu trusty *
Linux-lts-utopic Ubuntu upstream *
Linux-lts-vivid Ubuntu trusty *
Linux-lts-vivid Ubuntu upstream *
Linux-lts-wily Ubuntu trusty *
Linux-lts-wily Ubuntu upstream *
Linux-lts-xenial Ubuntu trusty *
Linux-lts-xenial Ubuntu trusty/esm *
Linux-lts-xenial Ubuntu upstream *
Linux-maguro Ubuntu trusty *
Linux-maguro Ubuntu upstream *
Linux-mako Ubuntu trusty *
Linux-mako Ubuntu upstream *
Linux-mako Ubuntu xenial *
Linux-manta Ubuntu trusty *
Linux-manta Ubuntu upstream *
Linux-oem Ubuntu bionic *
Linux-oem Ubuntu cosmic *
Linux-oem Ubuntu disco *
Linux-oem Ubuntu eoan *
Linux-oem Ubuntu upstream *
Linux-oem Ubuntu xenial *
Linux-oem-5.4 Ubuntu upstream *
Linux-oem-osp1 Ubuntu bionic *
Linux-oem-osp1 Ubuntu disco *
Linux-oem-osp1 Ubuntu eoan *
Linux-oem-osp1 Ubuntu upstream *
Linux-oracle Ubuntu bionic *
Linux-oracle Ubuntu cosmic *
Linux-oracle Ubuntu disco *
Linux-oracle Ubuntu esm-infra/xenial *
Linux-oracle Ubuntu upstream *
Linux-oracle Ubuntu xenial *
Linux-oracle-5.0 Ubuntu upstream *
Linux-raspi2 Ubuntu bionic *
Linux-raspi2 Ubuntu cosmic *
Linux-raspi2 Ubuntu disco *
Linux-raspi2 Ubuntu upstream *
Linux-raspi2-5.3 Ubuntu upstream *
Linux-snapdragon Ubuntu bionic *
Linux-snapdragon Ubuntu disco *
Linux-snapdragon Ubuntu upstream *

Extended Description

This can have security implications when the expected synchronization is in security-critical code, such as recording whether a user is authenticated or modifying important state information that should not be influenced by an outsider. A race condition occurs within concurrent environments, and is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc. A race condition violates these properties, which are closely related:

A race condition exists when an “interfering code sequence” can still access the shared resource, violating exclusivity. Programmers may assume that certain code sequences execute too quickly to be affected by an interfering code sequence; when they are not, this violates atomicity. For example, the single “x++” statement may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read (the original value of x), followed by a computation (x+1), followed by a write (save the result to x). The interfering code sequence could be “trusted” or “untrusted.” A trusted interfering code sequence occurs within the program; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable program.

Potential Mitigations

  • Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
  • Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

References