CVE-2021-45257

Publication date 22 December 2021

Last updated 15 September 2025

Ubuntu priority

Why this priority?

Cvss 3 Severity Score

Score breakdown

Description

An infinite loop vulnerability exists in nasm 2.16rc0 via the gpaste_tokens function.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
nasm	25.10 questing	Vulnerable
	25.04 plucky	Vulnerable
	24.10 oracular	Ignored end of life, was needs-triage
	24.04 LTS noble	Vulnerable
	23.10 mantic	Ignored end of life, was needs-triage
	23.04 lunar	Ignored end of life, was needs-triage
	22.10 kinetic	Ignored end of life, was needs-triage
	22.04 LTS jammy	Vulnerable
	21.10 impish	Ignored end of life
	21.04 hirsute	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	Ignored end of standard support

Notes

allenpthuang

The bug tracker is down. Wayback Machine link added. The function should be `paste_tokens`. The issue seems to be introduced at 4c0bd9e (>= 2.15.03). The POC works on versions above 2.15.03. No patch is currently made available as of 2025-09-12.

Severity score breakdown

Parameter	Value
Base score	5.5 · Medium
Attack vector	Local
Attack complexity	Low
Privileges required	None
User interaction	Required
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H