CVE-2021-33912

Publication date 19 January 2022

Last updated 25 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

9.8 · Critical

Score breakdown

Description

libspf2 before 1.2.11 has a four-byte heap-based buffer overflow that might allow remote attackers to execute arbitrary code (via an unauthenticated e-mail message from anywhere on the Internet) with a crafted SPF DNS record, because of incorrect sprintf usage in SPF_record_expand_data in spf_expand.c. The vulnerable code may be part of the supply chain of a site's e-mail infrastructure (e.g., with additional configuration, Exim can use libspf2; the Postfix web site links to unofficial patches for use of libspf2 with Postfix; older versions of spfquery relied on libspf2) but most often is not.

Status

Package Ubuntu Release Status
libspf2 24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic Ignored end of life, was needs-triage
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 1.2.10-7+deb9u2build0.20.04.1
18.04 LTS bionic
Fixed 1.2.10-7ubuntu0.18.04.1~esm1
16.04 LTS xenial
Fixed 1.2.10-6ubuntu0.1~esm2

Get expanded security coverage with Ubuntu Pro

Reduce your average CVE exposure time from 98 days to 1 day with expanded CVE patching, ten-years security maintenance and optional support for the full stack of open-source applications. Free for personal use.

Get Ubuntu Pro 30-day free trial

Severity score breakdown

Parameter Value
Base score 9.8 · Critical
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

    • USN-6584-1
    • Libspf2 vulnerabilities
    • 15 January 2024
    • USN-6584-2
    • Libspf2 vulnerabilities
    • 21 February 2024

Other references