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Security Advisory

USN-4578-1: Linux kernel vulnerabilities

Severity

High

Vendor

Canonical Ubuntu

Versions Affected

  • Canonical Ubuntu 16.04

Description

Hador Manor discovered that the DCCP protocol implementation in the Linux kernel improperly handled socket reuse, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-16119)

Wen Xu discovered that the XFS file system in the Linux kernel did not properly validate inode metadata in some situations. An attacker could use this to construct a malicious XFS image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10322)

It was discovered that the btrfs file system in the Linux kernel contained a use-after-free vulnerability when merging free space. An attacker could use this to construct a malicious btrfs image that, when mounted and operated on, could cause a denial of service (system crash). (CVE-2019-19448)

Jay Shin discovered that the ext4 file system implementation in the Linux kernel did not properly handle directory access with broken indexing, leading to an out-of-bounds read vulnerability. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-14314)

Giuseppe Scrivano discovered that the overlay file system in the Linux kernel did not properly perform permission checks in some situations. A local attacker could possibly use this to bypass intended restrictions and gain read access to restricted files. (CVE-2020-16120)

It was discovered that the NFS client implementation in the Linux kernel did not properly perform bounds checking before copying security labels in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-25212)

It was discovered that the NFC implementation in the Linux kernel did not properly perform permissions checks when opening raw sockets. A local attacker could use this to create or listen to NFC traffic. (CVE-2020-26088)

CVEs contained in this USN include: CVE-2018-10322, CVE-2020-25212, CVE-2020-16119, CVE-2020-16120, CVE-2020-14314, CVE-2020-26088, CVE-2019-19448.

Affected Cloud Foundry Products and Versions

Severity is high unless otherwise noted.

  • Xenial Stemcells
    • 315.x versions prior to 315.196
    • 456.x versions prior to 456.123
    • 621.x versions prior to 621.87
    • 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 315.x versions to 315.196 or greater
    • Upgrade 456.x versions to 456.123 or greater
    • Upgrade 621.x versions to 621.87 or greater
    • All other stemcells should be upgraded to the latest version available on bosh.io.

History

2020-11-20: Initial vulnerability report published.

Cloud Foundry Foundation Security Team Profile Image

Cloud Foundry Foundation Security Team, AUTHOR

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