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Amazon Linux 2 : libsepol (ALAS-2023-2307)

low Nessus Plugin ID 183473

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Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of libsepol installed on the remote host is prior to 2.5-10. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2023-2307 advisory.

 - The CIL compiler in SELinux 3.2 has a use-after-free in __cil_verify_classperms (called from
 __cil_verify_classpermission and __cil_pre_verify_helper). (CVE-2021-36084)

 - The CIL compiler in SELinux 3.2 has a use-after-free in __cil_verify_classperms (called from
 __verify_map_perm_classperms and hashtab_map). (CVE-2021-36085)

 - The CIL compiler in SELinux 3.2 has a use-after-free in cil_reset_classpermission (called from cil_reset_classperms_set and cil_reset_classperms_list). (CVE-2021-36086)

 - The CIL compiler in SELinux 3.2 has a heap-based buffer over-read in ebitmap_match_any (called indirectly from cil_check_neverallow). This occurs because there is sometimes a lack of checks for invalid statements in an optional block. (CVE-2021-36087)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Run 'yum update libsepol' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALAS-2023-2307.html

https://alas.aws.amazon.com/cve/html/CVE-2021-36084.html

https://alas.aws.amazon.com/cve/html/CVE-2021-36085.html

https://alas.aws.amazon.com/cve/html/CVE-2021-36086.html

https://alas.aws.amazon.com/cve/html/CVE-2021-36087.html

https://alas.aws.amazon.com/faqs.html

Plugin Details

Severity: Low

ID: 183473

File Name: al2_ALAS-2023-2307.nasl

Version: 1.1

Type: local

Agent: unix

Published: 10/20/2023

Updated: 10/23/2023

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 2.2

CVSS v2

Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2021-36087

CVSS v3

Risk Factor: Low

Base Score: 3.3

Temporal Score: 3

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:libsepol-devel, p-cpe:/a:amazon:linux:libsepol-static, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:libsepol, p-cpe:/a:amazon:linux:libsepol-debuginfo

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 10/12/2023

Vulnerability Publication Date: 7/1/2021

Reference Information

CVE: CVE-2021-36084, CVE-2021-36085, CVE-2021-36086, CVE-2021-36087