Severity

Medium

Vendor

Canonical Ubuntu

Versions Affected

• Canonical Ubuntu 16.04

Description

It was discovered that the network block device (nbd) implementation in the Linux kernel did not properly check for error conditions in some situations. An attacker could possibly use this to cause a denial of service (system crash). (CVE-2019-16089)

It was discovered that the btrfs file system implementation in the Linux kernel did not properly validate file system metadata in some situations. An attacker could use this to construct a malicious btrfs image that, when mounted, could cause a denial of service (system crash). (CVE-2019-19036, CVE-2019-19318, CVE-2019-19813, CVE-2019-19816)

It was discovered that the btrfs implementation in the Linux kernel did not properly detect that a block was marked dirty in some situations. An attacker could use this to specially craft a file system image that, when unmounted, could cause a denial of service (system crash). (CVE-2019-19377)

It was discovered that the kernel->user space relay implementation in the Linux kernel did not properly check return values in some situations. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2019-19462)

Matthew Sheets discovered that the SELinux network label handling implementation in the Linux kernel could be coerced into de-referencing a NULL pointer. A remote attacker could use this to cause a denial of service (system crash). (CVE-2020-10711)

It was discovered that the SCSI generic (sg) driver in the Linux kernel did not properly handle certain error conditions correctly. A local privileged attacker could use this to cause a denial of service (system crash). (CVE-2020-12770)

It was discovered that the USB Gadget device driver in the Linux kernel did not validate arguments passed from configfs in some situations. A local attacker could possibly use this to cause a denial of service (system crash) or possibly expose sensitive information. (CVE-2020-13143)

It was discovered that the efi subsystem in the Linux kernel did not handle memory allocation failures during early boot in some situations. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2019-12380)

It was discovered that the btrfs file system in the Linux kernel in some error conditions could report register information to the dmesg buffer. A local attacker could possibly use this to expose sensitive information. (CVE-2019-19039)

CVEs contained in this USN include: CVE-2019-19377, CVE-2020-10711, CVE-2020-12770, CVE-2020-13143, CVE-2019-19318, CVE-2019-19816, CVE-2019-19036, CVE-2019-19462, CVE-2019-12380, CVE-2019-19039, CVE-2019-19813, CVE-2019-16089.

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

• Xenial Stemcells
  • 170.x versions prior to 170.222
  • 250.x versions prior to 250.201
  • 315.x versions prior to 315.188
  • 456.x versions prior to 456.115
  • 621.x versions prior to 621.77
  • 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 170.x versions to 170.222 or greater
  • Upgrade 250.x versions to 250.201 or greater
  • Upgrade 315.x versions to 315.188 or greater
  • Upgrade 456.x versions to 456.115 or greater
  • Upgrade 621.x versions to 621.77 or greater
  • All other stemcells should be upgraded to the latest version available on bosh.io.

References

• USN Notice
• CVE-2019-19377
• CVE-2020-10711
• CVE-2020-12770
• CVE-2020-13143
• CVE-2019-19318
• CVE-2019-19816
• CVE-2019-19036
• CVE-2019-19462
• CVE-2019-12380
• CVE-2019-19039
• CVE-2019-19813
• CVE-2019-16089

History

2020-07-06: Initial vulnerability report published.