SB2024080664 - Amazon Linux AMI update for libsepol

Description

This security bulletin contains information about 4 vulnerabilities.

1) Use-after-free (CVE-ID: CVE-2021-36084)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a use-after-free error within the __cil_verify_classperms() function in CIL compiler in SELinux. A local user can perform a denial of service (DoS) attack.

2) Use-after-free (CVE-ID: CVE-2021-36085)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a use-after-free error within the __cil_verify_classperms() function in CIL compiler in SELinux. A local user can perform a denial of service (DoS) attack.

3) Use-after-free (CVE-ID: CVE-2021-36086)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a use-after-free error within the cil_reset_classpermission() function in CIL compiler in SELinux. A local user can perform a denial of service (DoS) attack.

4) Out-of-bounds read (CVE-ID: CVE-2021-36087)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error in the ebitmap_match_any() function within the CIL compiler in SELinux. A local user can trigger an out-of-bounds read error and perform denial of service attack.

Remediation

Install update from vendor's website.

References

• https://alas.aws.amazon.com/AL2023/ALAS-2023-017.html