CVE Vulnerabilities

CVE-2019-7656

Incorrect Permission Assignment for Critical Resource

Published: Jan 29, 2020 | Modified: May 03, 2022
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 privilege escalation vulnerability in Wowza Streaming Engine 4.8.0 and earlier allows any unprivileged Linux user to escalate privileges to root. The installer sets too relaxed permissions on /usr/local/WowzaStreamingEngine/bin/* core program files. By injecting a payload into one of those files, it will run with the same privileges as the Wowza server, root. For example, /usr/local/WowzaStreamingEngine/bin/tune.sh could be replaced with a Trojan horse. This issue was resolved in Wowza Streaming Engine 4.8.5.

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
Streaming_engine Wowza * 4.8.0 (including)

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