CVE-2018-7738

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: 2018-03-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-7738 is rated Moderate Risk (44.2/100): CVSS High severity, with low exploitation likelihood (EPSS 0.46%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

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

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.05% 0.46% +0.40%
2 2025-11-21 0.05% 0.05% +0.01%
3 2025-11-18 — 0.05% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-7738

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.0 HIGH
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.9 10.0 [email protected]

Weakness enumeration for CVE-2018-7738

OS Trackers for CVE-2018-7738

vendor priority summary link
debian unimportant CVE-2018-7738 unimportant priority: Debian including 2 source packages (bash-completion, util-linux), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5, resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-7738
gentoo high CVE-2018-7738: 1 GLSA(s) (201803-02), 1 atom(s) (sys-apps/util-linux); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2018-7738
redhat medium — https://access.redhat.com/security/cve/CVE-2018-7738
suse high CVE-2018-7738 severity important: SUSE including 541 source package names (0.9.1:libblkid1-2.29.2-3.8.1, 0.9.1:libfdisk1-2.29.2-3.8.1, …), 1021 product×package rows across 97 product lines (Container caasp/v4/cilium, Container caasp/v4/cilium-operator, … (97 product lines)): Fixed 740, Known Affected 231, Known Not Affected 50. https://www.suse.com/security/cve/CVE-2018-7738/
ubuntu negligible CVE-2018-7738 negligible priority: Ubuntu including 2 source packages (bash-completion, util-linux), 18 status rows across 9 suites (artful, bionic, cosmic, disco, eoan, focal, trusty, upstream, xenial): not-affected 10, ignored 5, released 2, needs-triage 1. https://ubuntu.com/security/CVE-2018-7738

Affected software / configurations for CVE-2018-7738

Vendor Product Version Raw CPE
kernel util-linux <= 2.31 cpe:2.3:a:kernel:util-linux:*:*:*:*:*:*:*:*

References for CVE-2018-7738

cvelogic Threat Intelligence