#VU56240 Buffer overflow in Linux kernel - CVE-2021-29650

Vulnerability identifier: #VU56240

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-2021-29650

CWE-ID: CWE-119

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 a boundary error within the netfilter subsystem in net/netfilter/x_tables.c and include/linux/netfilter/x_tables.h. A local user can trigger memory corruption upon the assignment of a new table value and cause denial of service.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 5.11.11, 5.11.11

---

External links
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=175e476b8cdf2a4de7432583b49c871345e4f8a1
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.11
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WKRNELXLVFDY6Y5XDMWLIH3VKIMQXLLR/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RZGMUP6QEHJJEKPMLKOSPWYMW7PXFC2M/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VTADK5ELGTATGW2RK3K5MBJ2WGYCPZCM/
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html
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.