CVE-2021-38371

Publication date 10 August 2021

Last updated 25 August 2025

Ubuntu priority

Low

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

The STARTTLS feature in Exim through 4.94.2 allows response injection (buffering) during MTA SMTP sending.

Read the notes from the security team

Status

Package Ubuntu Release Status
exim4 24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.10 impish Ignored end of life
21.04 hirsute Ignored end of life
20.04 LTS focal
Fixed 4.93-13ubuntu1.11
18.04 LTS bionic
Fixed 4.90.1-1ubuntu1.10+esm4
16.04 LTS xenial
Fixed 4.86.2-2ubuntu2.6+esm7
14.04 LTS trusty
Fixed 4.82-3ubuntu2.4+esm8

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Notes

mdeslaur

the upstream Exim developers do not consider this to be a security issue, and do not believe this to be exploitable. See exim4 advisory.

Patch details

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

Package Patch details
exim4

Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact High
Availability impact None
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References

Related Ubuntu Security Notices (USN)

Other references