CVE Vulnerabilities

CVE-2019-1596

Incorrect Permission Assignment for Critical Resource

Published: Mar 07, 2019 | Modified: Oct 08, 2020
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
7.2 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C
RedHat/V2
RedHat/V3
Ubuntu

A vulnerability in the Bash shell implementation for Cisco NX-OS Software could allow an authenticated, local attacker to escalate their privilege level to root. The attacker must authenticate with valid user credentials. The vulnerability is due to incorrect permissions of a system executable. An attacker could exploit this vulnerability by authenticating to the device and entering a crafted command at the Bash prompt. A successful exploit could allow the attacker to escalate their privilege level to root. Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I7(4). Nexus 3500 Platform Switches are affected in versions prior to 7.0(3)I7(4). Nexus 3600 Platform Switches are affected in versions prior to 7.0(3)F3(5). Nexus 9000 Series Switches in Standalone NX-OS Mode are affected in versions prior to 7.0(3)I7(4). Nexus 9500 R-Series Line Cards and Fabric Modules are affected in versions prior to 7.0(3)F3(5).

Weakness

The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.

Affected Software

Name Vendor Start Version End Version
Nx-os Cisco * 7.0(3)i4(9) (excluding)
Nx-os Cisco 7.0(3)i5 (including) 7.0(3)i7(4) (excluding)

Potential Mitigations

  • Run the code in a “jail” or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
  • OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.
  • This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.
  • Be careful to avoid CWE-243 and other weaknesses related to jails.

References