PT-2021-21416 · Qpdf+5 · Qpdf+5

Bin2415 · Published 2020-12-23 · Updated 2025-08-27 · CVE-2021-36978

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions QPDF versions 9.x through 9.1.1 QPDF versions 10.x through 10.0.4

Description The issue is a heap-based buffer overflow in Pl ASCII85Decoder::write, which is called from Pl AES PDF::flush and Pl AES PDF::finish, occurring when a certain downstream write fails.

Recommendations For QPDF versions 9.x through 9.1.1, update to a version later than 9.1.1 to resolve the issue. For QPDF versions 10.x through 10.0.4, update to a version later than 10.0.4 to resolve the issue. As a temporary workaround, consider restricting the use of the Pl ASCII85Decoder::write function until a patch is available.

Fix

DoS

Memory Corruption

Weakness Enumeration

CWE-787

Related Identifiers

ALT-PU-2021-1011

ALT-PU-2022-1049

ALT-PU-2023-4131

BDU:2025-10921

CVE-2021-36978

DLA-3548-1

OPENSUSE-SU-2022_2670-1

OPENSUSE-SU-2022_3248-1

SUSE-SU-2022:2669-1

SUSE-SU-2022:2670-1

SUSE-SU-2022:3248-1

SUSE-SU-2022_2669-1

SUSE-SU-2022_2670-1

SUSE-SU-2022_3248-1

USN-5026-1

USN-5026-2

Affected Products

Alt Linux

Linuxmint

Qpdf

Red Os

Suse

Ubuntu

References · 39

• https://github.com/qpdf/qpdf/commit/dc92574c10f3e2516ec6445b88c5d584f40df4e5 · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-36978 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:2669-1 · Vendor Advisory
• https://bdu.fstec.ru/vul/2025-10921 · Security Note
• https://wiki.astralinux.ru/astra-linux-se47-bulletin-2026-0518SE47 · Vendor Advisory
• https://osv.dev/vulnerability/DLA-3548-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2018-18020 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-36978 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-5026-2 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:3248-1 · Vendor Advisory
• https://osv.dev/vulnerability/USN-5026-1 · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se17-bulletin-2026-0421SE17 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-36978 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-36978 · Vendor Advisory
• https://security.gentoo.org/glsa/202401-20 · Vendor Advisory