USN-4999-1: Linux kernel vulnerabilities

Published Jun 23, 2021
·
Updated

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) Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the Linux kernel contained a reference counting error. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-25670) Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the Linux kernel did not properly deallocate memory in certain error situations. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2020-25671, CVE-2020-25672) Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the Linux kernel did not properly handle error conditions in some situations, leading to an infinite loop. A local attacker could use this to cause a denial of service. (CVE-2020-25673) 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 Linux kernel’s WiFi implementation accepted plaintext fragments in certain situations. A physically proximate attacker could use this issue to inject packets. (CVE-2020-26145) Mathy Vanhoef discovered that the Linux kernel’s WiFi implementation could reassemble 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) Piotr Krysiuk and Benedict Schlueter discovered that the eBPF implementation in the Linux kernel performed out of bounds speculation on pointer arithmetic. A local attacker could use this to expose sensitive information. (CVE-2021-29155) Manfred Paul discovered that the extended Berkeley Packet Filter (eBPF) implementation in the Linux kernel contained an out-of-bounds vulnerability. A local attacker could use this issue to execute arbitrary code. (CVE-2021-31440) 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)

Affected Software

1 affected component
Canonical Linux kernel

Event History

May 10, 2025
Advisory Published
via Ubuntu·03:47 AM
Data Sourced
via Ubuntu·03:47 AM
DescriptionAffected Software

Frequently Asked Questions

1

What is the severity of USN-4999-1?

The severity of USN-4999-1 is classified as high due to the potential for local attackers to execute arbitrary code.

2

How do I fix USN-4999-1?

To fix USN-4999-1, users should update their system packages to the latest recommended versions as specified in the advisory.

3

Which Ubuntu versions are affected by USN-4999-1?

USN-4999-1 affects Ubuntu 20.10, specifically targeting various kernel image packages.

4

What vulnerabilities are addressed in USN-4999-1?

USN-4999-1 addresses multiple use-after-free vulnerabilities related to a race condition in the Linux kernel's CAN BCM networking protocol.

5

Can I check if my system is vulnerable to USN-4999-1?

You can check if your system is vulnerable to USN-4999-1 by reviewing the installed kernel version against the versions listed in the security advisory.

Contact

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