CVE-2018-18584

In mspack/cab.h in libmspack before 0.8alpha and cabextract before 1.8, the CAB block input buffer is one byte too small for the maximal Quantum block, leading to an out-of-bounds write.

Published: 2018-10-23 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-18584 is rated Moderate Risk (57.2/100): CVSS Medium severity, with high exploitation likelihood (EPSS 5.83%, 91th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize 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-2018-18584

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 2026-05-26 6.37% 5.83% -0.54%
2 2025-12-28 5.43% 6.37% +0.94%
3 2025-12-27 — 5.43% —

Full EPSS history (25 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-18584

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2018-18584

OS Trackers for CVE-2018-18584

vendor priority summary link
alpine medium CVE-2018-18584: 2 source package rows (cabextract, libmspack); 18 state rows across 9 repos (3.10-main, 3.11-main, 3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 18, open 0. https://security.alpinelinux.org/vuln/CVE-2018-18584
debian not yet assigned CVE-2018-18584 not yet assigned priority: Debian including 2 source packages (cabextract, libmspack), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10. https://security-tracker.debian.org/tracker/CVE-2018-18584
gentoo normal CVE-2018-18584: 1 GLSA(s) (201903-20), 2 atom(s) (app-arch/cabextract, dev-libs/libmspack); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2018-18584
redhat medium — https://access.redhat.com/security/cve/CVE-2018-18584
ubuntu medium CVE-2018-18584 medium priority: Ubuntu including 3 source packages (cabextract, clamav, libmspack), 36 status rows across 12 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, trusty, upstream, xenial): not-affected 27, released 7, needs-triage 2. https://ubuntu.com/security/CVE-2018-18584

Affected software / configurations for CVE-2018-18584

Vendor Product Version Raw CPE
cabextract_project cabextract < 1.8 cpe:2.3:a:cabextract_project:cabextract:*:*:*:*:*:*:*:*
libmspack_project libmspack 0.3 cpe:2.3:a:libmspack_project:libmspack:0.3:alpha:*:*:*:*:*:*
libmspack_project libmspack 0.4 cpe:2.3:a:libmspack_project:libmspack:0.4:alpha:*:*:*:*:*:*
libmspack_project libmspack 0.5 cpe:2.3:a:libmspack_project:libmspack:0.5:alpha:*:*:*:*:*:*
libmspack_project libmspack 0.6 cpe:2.3:a:libmspack_project:libmspack:0.6:alpha:*:*:*:*:*:*
libmspack_project libmspack 0.7 cpe:2.3:a:libmspack_project:libmspack:0.7:alpha:*:*:*:*:*:*
libmspack_project libmspack 0.7.1 cpe:2.3:a:libmspack_project:libmspack:0.7.1:alpha:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.10 cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
suse linux_enterprise_server 11 cpe:2.3:o:suse:linux_enterprise_server:11:sp3:*:*:ltss:*:*:*
suse linux_enterprise_server 12 cpe:2.3:o:suse:linux_enterprise_server:12:ga:*:*:ltss:*:*:*
suse linux_enterprise_server 12 cpe:2.3:o:suse:linux_enterprise_server:12:sp1:*:*:ltss:*:*:*
suse linux_enterprise_server 12 cpe:2.3:o:suse:linux_enterprise_server:12:sp2:*:*:ltss:*:*:*
starwindsoftware starwind_virtual_san — cpe:2.3:a:starwindsoftware:starwind_virtual_san:-:*:*:*:*:vsphere:*:*

References for CVE-2018-18584

URL Tags
https://access.redhat.com/errata/RHSA-2019:2049 Third Party Advisory
https://bugs.debian.org/911640 Mailing List Third Party Advisory
https://github.com/kyz/libmspack/commit/40ef1b4093d77ad3a5cfcee1f5cb6108b3a3bcc2 Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/10/msg00017.html Mailing List Third Party Advisory
https://security.gentoo.org/glsa/201903-20 Third Party Advisory
https://usn.ubuntu.com/3814-1/ Third Party Advisory
https://usn.ubuntu.com/3814-2/ Third Party Advisory
https://usn.ubuntu.com/3814-3/ Third Party Advisory
https://www.cabextract.org.uk/#changes Product Vendor Advisory
https://www.openwall.com/lists/oss-security/2018/10/22/1 Mailing List Third Party Advisory
https://www.starwindsoftware.com/security/sw-20181213-0001/ Third Party Advisory
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