USN-4680-1: Linux kernel vulnerabilities

Severity

Medium

Vendor

Canonical Ubuntu

Description

It was discovered that debugfs in the Linux kernel as used by blktrace contained a use-after-free in some situations. A privileged local attacker could possibly use this to cause a denial of service (system crash). (CVE-2019-19770)

It was discovered that a race condition existed in the binder IPC implementation in the Linux kernel, 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-2020-0423)

Daniele Antonioli, Nils Ole Tippenhauer, and Kasper Rasmussen discovered that legacy pairing and secure-connections pairing authentication in the Bluetooth protocol could allow an unauthenticated user to complete authentication without pairing credentials via adjacent access. A physically proximate attacker could use this to impersonate a previously paired Bluetooth device. (CVE-2020-10135)

It was discovered that the console keyboard driver in the Linux kernel contained a race condition. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-25656)

Minh Yuan discovered that the tty driver in the Linux kernel contained race conditions when handling fonts. A local attacker could possibly use this to expose sensitive information (kernel memory). (CVE-2020-25668)

Keyu Man discovered that the ICMP global rate limiter in the Linux kernel could be used to assist in scanning open UDP ports. A remote attacker could use to facilitate attacks on UDP based services that depend on source port randomization. (CVE-2020-25705)

Jinoh Kang discovered that the Xen event channel infrastructure in the Linux kernel contained a race condition. An attacker in guest could possibly use this to cause a denial of service (dom0 crash). (CVE-2020-27675)

Daniel Axtens discovered that PowerPC RTAS implementation in the Linux kernel did not properly restrict memory accesses in some situations. A privileged local attacker could use this to arbitrarily modify kernel memory, potentially bypassing kernel lockdown restrictions. (CVE-2020-27777)

Minh Yuan discovered that the framebuffer console driver in the Linux kernel did not properly handle fonts in some conditions. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-28974)

CVEs contained in this USN include: CVE-2020-10135, CVE-2020-25705, CVE-2020-0423, CVE-2020-28974, CVE-2020-25656, CVE-2020-27675, CVE-2020-27777, CVE-2019-19770, CVE-2020-25668.

Affected Cloud Foundry Products and Versions

Severity is medium unless otherwise noted.

• Xenial Stemcells
  • 456.x versions prior to 456.133
  • 621.x versions prior to 621.97
  • 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 456.133 or greater
  • Upgrade 621.x versions to 621.97 or greater
  • All other stemcells should be upgraded to the latest version available on bosh.io.

History

2021-02-10: Initial vulnerability report published.