Security Information / 2021 / Security Information -- DSA-4941-1 linux

Debian Security Advisory

DSA-4941-1 linux -- security update

Date Reported:

20 Jul 2021

Affected Packages:

linux

Vulnerable:

Yes

Security database references:

In Mitre's CVE dictionary: CVE-2020-36311, CVE-2021-3609, CVE-2021-33909, CVE-2021-34693.

More information:

Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service or information leaks.

• CVE-2020-36311

  A flaw was discovered in the KVM subsystem for AMD CPUs, allowing an attacker to cause a denial of service by triggering destruction of a large SEV VM.

• CVE-2021-3609

  Norbert Slusarek reported a race condition vulnerability in the CAN BCM networking protocol, allowing a local attacker to escalate privileges.

• CVE-2021-33909

  The Qualys Research Labs discovered a size_t-to-int conversion vulnerability in the Linux kernel's filesystem layer. An unprivileged local attacker able to create, mount, and then delete a deep directory structure whose total path length exceeds 1GB, can take advantage of this flaw for privilege escalation.

  Details can be found in the Qualys advisory at https://www.qualys.com/2021/07/20/cve-2021-33909/sequoia-local-privilege-escalation-linux.txt

• CVE-2021-34693

  Norbert Slusarek discovered an information leak in the CAN BCM networking protocol. A local attacker can take advantage of this flaw to obtain sensitive information from kernel stack memory.

For the stable distribution (buster), these problems have been fixed in version 4.19.194-3.

We recommend that you upgrade your linux packages.

For the detailed security status of linux please refer to its security tracker page at: https://security-tracker.debian.org/tracker/linux