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Fencer Intel
high 8.8

CVE-2021-33657 json

There is a heap overflow problem in video/SDL_pixels.c in SDL (Simple DirectMedia Layer) 2.x to 2.0.18 versions.

published 4y ago modified 3mo ago also EUVD-2021-20334 , JLSEC-2026-364

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.1%
EPSS 2.1% chance of exploitation in 30 days, percentile 81%
public exploits
0
none known

Summary

There is a heap overflow problem in video/SDL_pixels.c in SDL (Simple DirectMedia Layer) 2.x to 2.0.18 versions. By crafting a malicious .BMP file, an attacker can cause the application using this library to crash, denial of service or Code execution.

Patch / fix

  • julia SDL2_jll 2.0.20+0
  • libsdl2 Debian 14, Debian 13, Debian 12 2.0.20+dfsg-2
  • libsdl1.2 Debian 12 1.2.15+dfsg2-7

debian advisories DEBIAN-CVE-2021-33657

  • libsdl1.2 Ubuntu 18.04 LTS 1.2.15+dfsg2-0.1ubuntu0.2
  • libsdl1.2 Ubuntu Pro 14.04 LTS 1.2.15-8ubuntu1.1+esm2
  • libsdl1.2 Ubuntu Pro 16.04 LTS 1.2.15+dfsg1-3ubuntu0.1+esm1

ubuntu advisories UBUNTU-CVE-2021-33657

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • SDL2 SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +7 more 2.0.8-150000.3.21.1
  • SDL SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +11 more 1.2.15-15.17.1
  • SDL SLES 11 SP4-LTSS, SLE Point of Sale 11 SP3 1.2.13-106.21.1
  • SDL SLES for SAP 15 SP2, SLES for SAP 15 SP1, SLES for SAP 15 +20 more 1.2.15-150000.3.19.1
  • SDL2 SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLES 15 SP2-BCL +11 more 2.0.8-150200.11.6.1

suse advisories SUSE-SU-2022:1313-1SUSE-SU-2022:1312-1SUSE-SU-2022:14943-1SUSE-SU-2022:1273-1SUSE-SU-2022:1218-1

  • SDL openSUSE Tumbleweed 1.2.15-1.1
  • SDL2 openSUSE Tumbleweed 2.32.8-1.1
  • SDL2 openSUSE Tumbleweed 2.28.5-2.1

opensuse advisories openSUSE-SU-2025:15205-1openSUSE-SU-2025:15206-1openSUSE-SU-2024:13582-1

  • sdl2 Alpine 3.24, Alpine 3.23, Alpine 3.22 +6 more 2.0.18-r0

alpine advisories ALPINE-CVE-2021-33657

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2021-33657 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

2.06% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P
OSV 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
julia SDL2_jll
<2.0.20+0
2.0.20+0

Affected products

  • n/a SDL2

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.