Severity

Low

Vendor

Canonical Ubuntu

Versions Affected

• Canonical Ubuntu 16.04
• Canonical Ubuntu 18.04

Description

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: Run sudo ua fix USN-5391-1 to fix the vulnerability. The problem can be corrected by updating your system to the following package versions: libsepol1 – 2.4-2ubuntu0.1~esm1 libsepol1-dev – 2.4-2ubuntu0.1~esm1 sepol-utils – 2.4-2ubuntu0.1~esm1 Available with UA Infra or UA Desktop: https://ubuntu.com/advantage

CVEs contained in this USN include: CVE-2021-36084, CVE-2021-36085, CVE-2021-36086, CVE-2021-36087.

Affected Cloud Foundry Products and Versions

Severity is low unless otherwise noted.

• Bionic Stemcells
  • 1.x versions prior to 1.84
  • All other stemcells not listed.
• cflinuxfs3
  • All versions prior to 0.290.0
• CF Deployment
  • All versions prior to 20.2.0, or later versions with Bionic Stemcells prior to 1.84 or Xenial Stemcells prior to 621.241

Mitigation

Users of affected products are strongly encouraged to follow the mitigations below.

The Cloud Foundry project recommends upgrading the following releases:

• Bionic Stemcells
  • Upgrade 1.x versions to 1.84 or greater
  • All other stemcells should be upgraded to the latest version available on bosh.io.
• cflinuxfs3
  • Upgrade all versions to 0.290.0 or greater
• CF Deployment
  • Upgrade all versions to 20.2.0 or greater, upgrade Bionic Stemcells to 1.84 or greater, and upgrade Xenial Stemcells to 621.241 or greater

References

• USN Notice
• CVE-2021-36084
• CVE-2021-36085
• CVE-2021-36086
• CVE-2021-36087

History

2022-05-23: Initial vulnerability report published.