CVE-2020-36430

Publication date 20 July 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

libass 0.15.x before 0.15.1 has a heap-based buffer overflow in decode_chars (called from decode_font and process_text) because the wrong integer data type is used for subtraction.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libass	22.04 LTS jammy	Not affected
	21.10 impish	Not affected
	21.04 hirsute	Ignored end of life
	20.10 groovy	Ignored end of life
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

Notes

ccdm94

introduced by commit 910211f.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
libass	Upstream: 0171374

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.8 · High

Base metrics

Parameter	Value
Attack vector	Local
Attack complexity	Low
Privileges required	None
User interaction	Required
Scope	Unchanged
Confidentiality impact	High
Integrity impact	High
Availability impact	High

Scores

Parameter	Value
Base score	7.8 · High
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H