Rapid7 Vulnerability & Exploit Database

Ubuntu: USN-5380-1 (CVE-2019-18276): Bash vulnerability

Free InsightVM Trial No Credit Card Necessary
Watch Demo See how it all works
Back to Search

Ubuntu: USN-5380-1 (CVE-2019-18276): Bash vulnerability

Severity
7
CVSS
(AV:L/AC:L/Au:N/C:C/I:C/A:C)
Published
11/28/2019
Created
04/23/2022
Added
04/20/2022
Modified
03/22/2023

Description

An issue was discovered in disable_priv_mode in shell.c in GNU Bash through 5.0 patch 11. By default, if Bash is run with its effective UID not equal to its real UID, it will drop privileges by setting its effective UID to its real UID. However, it does so incorrectly. On Linux and other systems that support "saved UID" functionality, the saved UID is not dropped. An attacker with command execution in the shell can use "enable -f" for runtime loading of a new builtin, which can be a shared object that calls setuid() and therefore regains privileges. However, binaries running with an effective UID of 0 are unaffected.

Solution(s)

  • ubuntu-upgrade-bash

References

insightVM

Advanced vulnerability management analytics and reporting.
Key Features
Free InsightVM Trial View All Features

With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.

– Scott Cheney, Manager of Information Security, Sierra View Medical Center

;