[USN-5391-1] libsepol vulnerabilities


========================================================================== Ubuntu Security Notice USN-5391-1 April 27, 2022
libsepol vulnerabilities ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 21.10 – Ubuntu 20.04 LTS – Ubuntu 18.04 LTS – Ubuntu 16.04 ESM
Summary:
Several security issues were fixed in libsepol.
Software Description: – libsepol: SELinux library for manipulating binary security policies
Details:
Nicolas Iooss discovered that libsepol incorrectly handled memory when handling policies. An attacker could possibly use this issue to cause a crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-36084)
It was discovered that libsepol incorrectly handled memory when handling policies. An attacker could possibly use this issue to cause a crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-36085)
It was discovered that libsepol incorrectly handled memory when handling policies. An attacker could possibly use this issue to cause a crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affects Ubuntu 18.04 LTS, Ubuntu 20.04 LTS and Ubuntu 21.10. (CVE-2021-36086)
It was discovered that libsepol incorrectly validated certain data, leading to a heap overflow. An attacker could possibly use this issue to cause a crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-36087)
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 21.10:   libsepol1                       3.1-1ubuntu2.1   sepol-utils                     3.1-1ubuntu2.1
Ubuntu 20.04 LTS:   libsepol1                       3.0-1ubuntu0.1   sepol-utils                     3.0-1ubuntu0.1
Ubuntu 18.04 LTS:   libsepol1                       2.7-1ubuntu0.1   sepol-utils                     2.7-1ubuntu0.1
Ubuntu 16.04 ESM:   libsepol1                       2.4-2ubuntu0.1~esm1   sepol-utils                     2.4-2ubuntu0.1~esm1
In general, a standard system update will make all the necessary changes.
References:   ubuntu.com/security/notices/USN-5391-1   CVE-2021-36084, CVE-2021-36085, CVE-2021-36086, CVE-2021-36087
Package Information:   launchpad.net/ubuntu/+source/libsepol/3.1-1ubuntu2.1   launchpad.net/ubuntu/+source/libsepol/3.0-1ubuntu0.1   launchpad.net/ubuntu/+source/libsepol/2.7-1ubuntu0.1