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Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986596)
high Nessus Plugin ID 269008
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-2025-986596 advisory.In the Linux kernel, the following vulnerability has been resolved:
smack: tcp: ipv4, fix incorrect labeling
Currently, Smack mirrors the label of incoming tcp/ipv4 connections:
when a label 'foo' connects to a label 'bar' with tcp/ipv4, 'foo' always gets 'foo' in returned ipv4 packets. So, 1) returned packets are incorrectly labeled ('foo' instead of 'bar') 2) 'bar' can write to 'foo' without being authorized to write.
Here is a scenario how to see this:
* Take two machines, let's call them C and S, with active Smack in the default state (no settings, no rules, no labeled hosts, only builtin labels)
* At S, add Smack rule 'foo bar w' (labels 'foo' and 'bar' are instantiated at S at this moment)
* At S, at label 'bar', launch a program that listens for incoming tcp/ipv4 connections
* From C, at label 'foo', connect to the listener at S.
(label 'foo' is instantiated at C at this moment) Connection succeedes and works.
* Send some data in both directions.
* Collect network traffic of this connection.
All packets in both directions are labeled with the CIPSO of the label 'foo'. Hence, label 'bar' writes to 'foo' without being authorized, and even without ever being known at C.
If anybody cares: exactly the same happens with DCCP.
This behavior 1st manifested in release 2.6.29.4 (see Fixes below) and it looks unintentional. At least, no explanation was provided.
I changed returned packes label into the 'bar', to bring it into line with the Smack documentation claims.
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
Plugin Details
Severity: High
ID: 269008
File Name: unity_linux_UTSA-2025-986596.nasl
Version: 1.2
Type: local
Published: 10/7/2025
Updated: 10/15/2025
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 6.7
CVSS v2
Risk Factor: High
Base Score: 9
Temporal Score: 6.7
Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C
CVSS Score Source: CVE-2024-47659
CVSS v3
Risk Factor: High
Base Score: 8.8
Temporal Score: 7.7
Vector: CVSS:3.0/AV:N/AC:L/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/local_checks_enabled, Host/cpu, Host/UOS-Server/release, Host/UOS-Server/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 9/22/2025
Vulnerability Publication Date: 10/9/2024
Reference Information
CVE: CVE-2024-47659