Detections
Analytics
Unity Linux 20.1070e Security Update: kernel (UTSA-2025-987585)
medium Nessus Plugin ID 271015
Synopsis
The Unity Linux host is missing one or more security updates.Description
The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2025-987585 advisory.In the Linux kernel, the following vulnerability has been resolved:
serial: core: fix transmit-buffer reset and memleak
Commit 761ed4a94582 (tty: serial_core: convert uart_close to use tty_port_close) converted serial core to use tty_port_close() but failed to notice that the transmit buffer still needs to be freed on final close.
Not freeing the transmit buffer means that the buffer is no longer cleared on next open so that any ioctl() waiting for the buffer to drain might wait indefinitely (e.g. on termios changes) or that stale data can end up being transmitted in case tx is restarted.
Furthermore, the buffer of any port that has been opened would leak on driver unbind.
Note that the port lock is held when clearing the buffer pointer due to the ldisc race worked around by commit a5ba1d95e46e (uart: fix race between uart_put_char() and uart_shutdown()).
Also note that the tty-port shutdown() callback is not called for console ports so it is not strictly necessary to free the buffer page after releasing the lock (cf. d72402145ace (tty/serial: do not free trasnmit buffer page under port lock)).
Tenable has extracted the preceding description block directly from the Unity Linux security advisory.
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
Solution
Update the affected kernel package.See Also
http://www.nessus.org/u?34868d2e
Plugin Details
Severity: Medium
ID: 271015
File Name: unity_linux_UTSA-2025-987585.nasl
Version: 1.1
Type: local
Published: 10/21/2025
Updated: 10/21/2025
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 4.4
CVSS v2
Risk Factor: Medium
Base Score: 4.6
Temporal Score: 3.4
Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C
CVSS Score Source: CVE-2021-47527
CVSS v3
Risk Factor: Medium
Base Score: 5.5
Temporal Score: 4.8
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
Required KB Items: Host/local_checks_enabled, Host/cpu, Host/UOS-Server/release, Host/UOS-Server/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 10/15/2025
Vulnerability Publication Date: 1/28/2022
Reference Information
CVE: CVE-2021-47527