CVE-2021-32749

Severity CVSS v4.0:

Pending analysis

Type:

CWE-94 Code Injection

Publication date:

16/07/2021

Last modified:

07/11/2023

Description

fail2ban is a daemon to ban hosts that cause multiple authentication errors. In versions 0.9.7 and prior, 0.10.0 through 0.10.6, and 0.11.0 through 0.11.2, there is a vulnerability that leads to possible remote code execution in the mailing action mail-whois. Command `mail` from mailutils package used in mail actions like `mail-whois` can execute command if unescaped sequences (`\n~`) are available in "foreign" input (for instance in whois output). To exploit the vulnerability, an attacker would need to insert malicious characters into the response sent by the whois server, either via a MITM attack or by taking over a whois server. The issue is patched in versions 0.10.7 and 0.11.3. As a workaround, one may avoid the usage of action `mail-whois` or patch the vulnerability manually.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 8.10 HIGH
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

8.10

Severity 3.x

HIGH

Vector 2.0

AV:N/AC:M/Au:N/C:P/I:P/A:P CVSS v2.0 Severity and Metrics:

Base Score: 6.80 MEDIUM
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P

Attack Vector (AV): Network
Attack Complexity (AC): Medium
Authentication (Au): None
Confidentiality (C): Physical
Integrity (I): Physical
Availability (A): Physical

Base Score 2.0

6.80

Severity 2.0

MEDIUM

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:fail2ban:fail2ban::::::::		0.9.7 (including)
cpe:2.3:a:fail2ban:fail2ban::::::::	0.10.0 (including)	0.10.7 (excluding)
cpe:2.3:a:fail2ban:fail2ban::::::::	0.11.0 (including)	0.11.3 (excluding)
cpe:2.3:o:fedoraproject:fedora:34:::::::*
cpe:2.3:o:fedoraproject:fedora:35:::::::*

To consult the complete list of CPE names with products and versions, see this page

CVE-2021-32749

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools