Denial of service in Linux kernel FUSE implementation

1) Excessive Iteration

EUVDB-ID: #VU58207

Risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-28950

CWE-ID: CWE-834 - Excessive Iteration

Exploit availability: No

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to excessive iteration in fs/fuse/fuse_i.h in the Linux kernel. A local user can run a specially crafted program to perform a denial of service attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.11 - 5.11.7

External links

http://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.8
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=775c5033a0d164622d9d10dd0f0a5531639ed3ed
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QRTPQE73ANG7D6M4L4PK5ZQDPO4Y2FVD/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FB6LUXPEIRLZH32YXWZVEZAD4ZL6SDK2/
http://lists.debian.org/debian-lts-announce/2021/06/msg00020.html

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.