CVE-2020-28019

Publication date 4 May 2021

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

Exim 4 before 4.94.2 has Improper Initialization that can lead to recursion-based stack consumption or other consequences. This occurs because use of certain getc functions is mishandled when a client uses BDAT instead of DATA.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
exim4	22.04 LTS jammy	Fixed 4.94-15ubuntu1.2
	21.10 impish	Fixed 4.94-15ubuntu1.2
	21.04 hirsute	Fixed 4.94-15ubuntu1.2
	20.10 groovy	Fixed 4.94-7ubuntu1.2
	20.04 LTS focal	Fixed 4.93-13ubuntu1.5
	18.04 LTS bionic	Fixed 4.90.1-1ubuntu1.8
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

Notes

leosilva

trusty/xenial ESM not affected. vulnerability was introduced by: https://git.exim.org/exim.git/patch/7e3ce68e68ab9b8906a637d352993abf361554e2

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Base metrics

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

Scores

Parameter	Value
Base score	7.5 · High
Exploitability score	-
Impact score	-

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

References

Related Ubuntu Security Notices (USN)

USN-4934-1
Exim vulnerabilities
4 May 2021

Other references

https://www.cve.org/CVERecord?id=CVE-2020-28019