USN-5000-1: Linux kernel vulnerabilities

Severity

High

Vendor

Canonical Ubuntu

Description

Norbert Slusarek discovered a race condition in the CAN BCM networking protocol of the Linux kernel leading to multiple use-after-free vulnerabilities. A local attacker could use this issue to execute arbitrary code. (CVE-2021-3609)

Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel did not properly enforce limits for pointer operations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-33200)

Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation did not properly clear received fragments from memory in some situations. A physically proximate attacker could possibly use this issue to inject packets or expose sensitive information. (CVE-2020-24586)

Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled encrypted fragments. A physically proximate attacker could possibly use this issue to decrypt fragments. (CVE-2020-24587)

Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled certain malformed frames. If a user were tricked into connecting to a malicious server, a physically proximate attacker could use this issue to inject packets. (CVE-2020-24588)

Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation incorrectly handled EAPOL frames from unauthenticated senders. A physically proximate attacker could inject malicious packets to cause a denial of service (system crash). (CVE-2020-26139)

Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation did not properly verify certain fragmented frames. A physically proximate attacker could possibly use this issue to inject or decrypt packets. (CVE-2020-26141)

Mathy Vanhoef discovered that the in the Linux kernel’s WiFi implementation leading to accepting plaintext fragments. A physically proximate attacker could use this issue to inject packets. (CVE-2020-26145)

Mathy Vanhoef discovered that the the Linux kernel’s WiFi implementation leading to reassembling mixed encrypted and plaintext fragments. A physically proximate attacker could possibly use this issue to inject packets or exfiltrate selected fragments. (CVE-2020-26147)

Or Cohen discovered that the SCTP implementation in the Linux kernel contained a race condition in some situations, leading to a use-after-free condition. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-23133)

Or Cohen and Nadav Markus discovered a use-after-free vulnerability in the nfc implementation in the Linux kernel. A privileged local attacker could use this issue to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-23134)

Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel did not properly prevent speculative loads in certain situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2021-31829)

It was discovered that a race condition in the kernel Bluetooth subsystem can lead to use-after-free of slab objects. An attacker could use this issue to possibly execute arbitrary code. (CVE-2021-32399)

It was discovered that a use-after-free existed in the Bluetooth HCI driver of the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-33034)

It was discovered that an out-of-bounds (OOB) memory access flaw in the f2fs module of the Linux kernel. A local attacker could use this issue to cause a denial of service (system crash). (CVE-2021-3506)

CVEs contained in this USN include: CVE-2021-31829, CVE-2021-33200, CVE-2021-23134, CVE-2021-3506, CVE-2020-24586, CVE-2020-24587, CVE-2021-32399, CVE-2020-24588, CVE-2020-26141, CVE-2021-33034, CVE-2020-26145, CVE-2020-26147, CVE-2021-3609, CVE-2020-26139, CVE-2021-23133.

Affected Cloud Foundry Products and Versions

Severity is high unless otherwise noted.

• Bionic Stemcells
  • 1.x versions prior to 1.13
  • 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:

• Bionic Stemcells
  • Upgrade 1.x versions to 1.13 or greater
  • All other stemcells should be upgraded to the latest version available on bosh.io.

History

2021-07-08: Initial vulnerability report published.