PT-2024-2977 · Linux+1 · Linux Kernel+1

Jonathon Reinhart · Published 2024-02-27 · Updated 2024-04-22 · CVE-2021-46912

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The issue is related to the Linux kernel, where tcp allowed congestion control is global and writable, allowing writes to it in any net namespace to leak into all other net namespaces. This is because tcp available congestion control and tcp allowed congestion control are the only sysctls in ipv4 net table with a NULL data pointer, and their handlers have no other way of referencing a struct net, thus operating globally. The intent of the commit was only to know which congestion algorithms are available or allowed, and making these entries read-only should be sufficient.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

BDU:2024-03149

CVE-2021-46912

Affected Products

Linux Kernel

Red Os

References · 15

• https://git.kernel.org/stable/c/35d7491e2f77ce480097cabcaf93ed409e916e12 · Patch
• https://bdu.fstec.ru/vul/2024-03149 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2021-46912 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2021-46912 · Vendor Advisory
• https://git.kernel.org/stable/c/97684f0970f6e112926de631fdd98d9693c7e5c1 · Patch
• https://security-tracker.debian.org/tracker/CVE-2021-46912 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-46912 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-46912 · Vendor Advisory
• https://git.kernel.org/stable/c/1ccdf1bed140820240e383ba0accc474ffc7f006 · Patch
• https://cve.org/CVERecord?id=CVE-2021-46912 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-46912 · Vendor Advisory
• https://git.kernel.org/linus/97684f0970f6e112926de631fdd98d9693c7e5c1 · Note
• https://redos.red-soft.ru/support/secure · Note
• https://redos.red-soft.ru/support/secure/uyazvimosti/support/secure/uyazvimosti/mnozhestvennye-uyazvimosti-yadra-os-18-04-24 · Note
• https://twitter.com/CVEnew/status/1762376174817222848 · Twitter Post