Amazon Linux AMI update for polkit

Published: 2024-08-06

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-4034 CVE-2021-4115
CWE-ID	CWE-20 CWE-400
Exploitation vector	Local
Public exploit	Vulnerability #1 is being exploited in the wild. Public exploit code for vulnerability #2 is available.
Vulnerable software	Amazon Linux AMI Operating systems & Components / Operating system polkit Operating systems & Components / Operating system package or component
Vendor	Amazon Web Services

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Input validation error

EUVDB-ID: #VU60007

Risk: Medium

CVSSv4.0: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Green]

CVE-ID: CVE-2021-4034

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to improper handling of the calling parameters count in the pkexec setuid binary, which causes the binary to execute environment variables as commands. A local user can craft environment variables in a way that they will be processed and executed by pkexec and execute arbitrary commands on the system as root.

Mitigation

Update the affected packages:

aarch64:
    polkit-libs-debuginfo-0.117-10.amzn2023.0.3.aarch64
    polkit-devel-0.117-10.amzn2023.0.3.aarch64
    polkit-debuginfo-0.117-10.amzn2023.0.3.aarch64
    polkit-libs-0.117-10.amzn2023.0.3.aarch64
    polkit-0.117-10.amzn2023.0.3.aarch64
    polkit-debugsource-0.117-10.amzn2023.0.3.aarch64

noarch:
    polkit-docs-0.117-10.amzn2023.0.3.noarch

src:
    polkit-0.117-10.amzn2023.0.3.src

x86_64:
    polkit-libs-debuginfo-0.117-10.amzn2023.0.3.x86_64
    polkit-debuginfo-0.117-10.amzn2023.0.3.x86_64
    polkit-devel-0.117-10.amzn2023.0.3.x86_64
    polkit-libs-0.117-10.amzn2023.0.3.x86_64
    polkit-0.117-10.amzn2023.0.3.x86_64
    polkit-debugsource-0.117-10.amzn2023.0.3.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

polkit: before 0.117-10

CPE2.3

External links

https://alas.aws.amazon.com/AL2023/ALAS-2023-026.html

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

2) Resource exhaustion

EUVDB-ID: #VU61268

Risk: Low

CVSSv4.0: 5.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2021-4115

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No