Severity
High
Vendor
Canonical Ubuntu
Versions Affected
- Canonical Ubuntu 14.04
- Canonical Ubuntu 16.04
Description
It was discovered that the overlayfs implementation in the Linux kernel did not properly validate the application of file system capabilities with respect to user namespaces. A local attacker could use this to gain elevated privileges. (CVE-2021-3493)
Piotr Krysiuk discovered that the BPF JIT compiler for x86 in the Linux kernel did not properly validate computation of branch displacements in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-29154)
CVEs contained in this USN include: CVE-2021-29154, CVE-2021-3493.
Affected Cloud Foundry Products and Versions
Severity is high unless otherwise noted.
- Xenial Stemcells
- 456.x versions prior to 456.158
- 621.x versions prior to 621.123
- All other stemcells not listed.
Mitigation
Users of affected products are strongly encouraged to follow the mitigations below. The Cloud Foundry project recommends upgrading the following releases:
- Xenial Stemcells
- Upgrade 456.x versions to 456.158 or greater
- Upgrade 621.x versions to 621.123 or greater
- All other stemcells should be upgraded to the latest version available on bosh.io.
References
History
2021-04-29: Initial vulnerability report published.
