CVE-2018-7738 : In util-linux before 2.32-rc1, bash-completion/umount allows local users to gain privileges by embedding shell commands

In util-linux before 2.32-rc1, bash-completion/umount allows local users to gain privileges by embedding shell commands in a mountpoint name, which is mishandled during a umount command (within Bash) by a different user, as demonstrated by logging in as root and entering umount followed by a tab character for autocompletion.

Published 2018-03-07 02:29:04

Updated 2020-09-25 18:15:13

Source MITRE

View at NVD, CVE.org

Exploit prediction scoring system (EPSS) score for CVE-2018-7738

EPSS FAQ

0.04%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 6 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2018-7738

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
7.2	HIGH	AV:L/AC:L/Au:N/C:C/I:C/A:C	3.9	10.0	NIST
Access Vector: Local Access Complexity: Low Authentication: None Confidentiality Impact: Complete Integrity Impact: Complete Availability Impact: Complete
7.8	HIGH	CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	1.8	5.9	NIST
Attack Vector: Local Attack Complexity: Low Privileges Required: Low User Interaction: None Scope: Unchanged Confidentiality: High Integrity: High Availability: High

References for CVE-2018-7738

https://github.com/karelzak/util-linux/issues/539

Bash completion for umount fails if mount point contains a space · Issue #539 · karelzak/util-linux · GitHub
Issue Tracking;Third Party Advisory
https://usn.ubuntu.com/4512-1/

USN-4512-1: util-linux vulnerability | Ubuntu security notices | Ubuntu
http://www.securityfocus.com/bid/103367

util-linux CVE-2018-7738 Local Privilege Escalation Vulnerability
Third Party Advisory;VDB Entry
https://www.debian.org/security/2018/dsa-4134

Debian -- Security Information -- DSA-4134-1 util-linux
Third Party Advisory
https://bugs.debian.org/892179

#892179 - util-linux: CVE-2018-7738: code execution in bash-completion for umount - Debian Bug report logs
Patch;Third Party Advisory
https://github.com/karelzak/util-linux/commit/75f03badd7ed9f1dd951863d75e756883d3acc55

bash-completion: (umount) use findmnt, escape a space in paths · karelzak/util-linux@75f03ba · GitHub
Patch;Third Party Advisory

Products affected by CVE-2018-7738

Kernel » Util-linux
Versions up to, including, (<=) 2.31
cpe:2.3:a:kernel:util-linux:*:*:*:*:*:*:*:*
Matching versions

Vulnerability Details : CVE-2018-7738

Exploit prediction scoring system (EPSS) score for CVE-2018-7738

CVSS scores for CVE-2018-7738

References for CVE-2018-7738

Products affected by CVE-2018-7738