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ubuntucveUbuntu.comUB:CVE-2021-34981
HistoryMay 07, 2024 - 12:00 a.m.

CVE-2021-34981

2024-05-0700:00:00
ubuntu.com
ubuntu.com
20
linux kernel
bluetooth
cmtp module
privilege escalation
vulnerability
local attackers
high-privileged code
double free
cap_net_admin

7.5 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

7.8 High

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

28.8%

Linux Kernel Bluetooth CMTP Module Double Free Privilege Escalation
Vulnerability. This vulnerability allows local attackers to escalate
privileges on affected installations of Linux Kernel. An attacker must
first obtain the ability to execute high-privileged code on the target
system in order to exploit this vulnerability. The specific flaw exists
within the CMTP module. The issue results from the lack of validating the
existence of an object prior to performing further free operations on the
object. An attacker can leverage this vulnerability to escalate privileges
and execute code in the context of the kernel. Was ZDI-CAN-11977.

Notes

Author Note
Priority reason: CAP_NET_ADMIN privileges are required
cascardo to exploit this requires CAP_NET_ADMIN in the init namespace (init_ns): cmtp_add_connection is called from do_cmtp_sock_ioctl, with command CMTPCONNADD, which checks for capable(CAP_NET_ADMIN).

7.5 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

7.8 High

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

28.8%