#VU58207 Excessive Iteration in Linux kernel - CVE-2021-28950

Vulnerability identifier: #VU58207

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-28950

CWE-ID: CWE-834

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

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