CVE-2021-20240

A flaw was found in gdk-pixbuf in versions before 2.42.0. An integer wraparound leading to an out of bounds write can occur when a crafted GIF image is loaded. An attacker may cause applications to crash or could potentially execute code on the victim system. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Published: 2021-05-28 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20240 is rated High Risk (65/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.35%). EPSS rose +1.29% over the last day, indicating growing attacker interest. 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-2021-20240

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 1.06% 2.35% +1.29%
2 2026-05-28 0.79% 1.06% +0.26%
3 2025-11-21 — 0.79% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20240

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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: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.
 2.8 5.9 [email protected]
8.3 2.0 HIGH
AV:N/AC:M/Au:N/C:P/I:P/A:C 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:P)
Partial integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.6 8.5 [email protected]

Weakness enumeration for CVE-2021-20240

OS Trackers for CVE-2021-20240

vendor priority summary link
alpine — CVE-2021-20240: 1 source package rows (gdk-pixbuf); 10 state rows across 8 repos (3.10-main, 3.11-main, 3.12-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 4, open 6. https://security.alpinelinux.org/vuln/CVE-2021-20240
debian not yet assigned CVE-2021-20240 not yet assigned priority: Debian including 1 source packages (gdk-pixbuf), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-20240
redhat high — https://access.redhat.com/security/cve/CVE-2021-20240
suse high CVE-2021-20240 severity important: SUSE including 10 source package names (gdk-pixbuf, gdk-pixbuf-devel, …), 260 product×package rows across 46 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (46 product lines)): Known Not Affected 260. https://www.suse.com/security/cve/CVE-2021-20240/
ubuntu medium CVE-2021-20240 medium priority: Ubuntu including 1 source packages (gdk-pixbuf), 6 status rows across 6 suites (bionic, focal, groovy, trusty, upstream, xenial): released 3, not-affected 2, DNE 1. https://ubuntu.com/security/CVE-2021-20240

Affected software / configurations for CVE-2021-20240

Vendor Product Version Raw CPE
gnome gdk-pixbuf < 2.39.2 cpe:2.3:a:gnome:gdk-pixbuf:*:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

References for CVE-2021-20240

cvelogic Threat Intelligence