CVE-2018-20547

Exp

There is an illegal READ memory access at caca/dither.c (function get_rgba_default) in libcaca 0.99.beta19 for 24bpp data.

Published: 2018-12-28 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-20547 is rated High Exploit Risk (74.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.80%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2018-20547

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2018-20547

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 1.01% 1.80% +0.79%
2 2026-03-27 0.86% 1.01% +0.15%
3 2025-12-28 — 0.86% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-20547

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/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:H)
Serious risk that confidential data gets exposed in a big 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 5.2 [email protected]
5.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/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:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 4.9 [email protected]

Weakness enumeration for CVE-2018-20547

OS Trackers for CVE-2018-20547

vendor priority summary link
alpine high CVE-2018-20547: 1 source package rows (libcaca); 7 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 0. https://security.alpinelinux.org/vuln/CVE-2018-20547
debian low CVE-2018-20547 low priority: Debian including 1 source packages (libcaca), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-20547
suse medium CVE-2018-20547 severity moderate: SUSE including 52 source package names (caca-utils, caca-utils-0.99.beta19.git20171003-3.3.7, …), 167 product×package rows across 53 product lines (SLES for SAP Applications 11 SP3, SUSE CaaS Platform 4.5, … (53 product lines)): Known Not Affected 106, Fixed 61. https://www.suse.com/security/cve/CVE-2018-20547/
ubuntu low CVE-2018-20547 low priority: Ubuntu including 1 source packages (libcaca), 5 status rows across 5 suites (bionic, cosmic, trusty, upstream, xenial): released 4, needs-triage 1. https://ubuntu.com/security/CVE-2018-20547

Affected software / configurations for CVE-2018-20547

Vendor Product Version Raw CPE
libcaca_project libcaca 0.99 cpe:2.3:a:libcaca_project:libcaca:0.99:beta19:*:*:*:*:*:*
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:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
fedoraproject fedora 36 cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*
opensuse leap 15.0 cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:*

References for CVE-2018-20547

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00033.html Mailing List Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1652624 Exploit Issue Tracking Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/01/msg00007.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6WFGYICNTMNDNMDDUV4G2RYFB5HNJCOV/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PC7EGOEQ5C4OD66ZUJJIIYEXBTZOCMZX/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZSBCRN6EGQJUVOSD4OEEQ6XORHEM2CUL/
https://usn.ubuntu.com/3860-1/ Third Party Advisory
https://usn.ubuntu.com/3860-2/ Third Party Advisory
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