Linux Distros Unpatched Vulnerability : CVE-2021-47281

high Nessus Plugin ID 229831

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Fix race of snd_seq_timer_open() The timer instance per queue is exclusive, and snd_seq_timer_open() should have managed the concurrent accesses. It looks as if it's checking the already existing timer instance at the beginning, but it's not right, because there is no protection, hence any later concurrent call of snd_seq_timer_open() may override the timer instance easily. This may result in UAF, as the leftover timer instance can keep running while the queue itself gets closed, as spotted by syzkaller recently. For avoiding the race, add a proper check at the assignment of tmr->timeri again, and return -EBUSY if it's been already registered. (CVE-2021-47281)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

Plugin Details

Severity: High

ID: 229831

File Name: unpatched_CVE_2021_47281.nasl

Version: 1.1

Type: local

Agent: unix

Family: Misc.

Published: 3/5/2025

Updated: 3/5/2025

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 6

Temporal Score: 4.4

Vector: CVSS2#AV:L/AC:H/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2021-47281

CVSS v3

Risk Factor: High

Base Score: 7

Temporal Score: 6.1

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 5/21/2024

Reference Information

CVE: CVE-2021-47281

Detections

Analytics