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Unity Linux 20.1050e Security Update: kernel (UTSA-2025-990149)

medium Nessus Plugin ID 272431

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-2025-990149 advisory.

 In the Linux kernel, the following vulnerability has been resolved:

 ip_gre: test csum_start instead of transport header

 GRE with TUNNEL_CSUM will apply local checksum offload on CHECKSUM_PARTIAL packets.

 ipgre_xmit must validate csum_start after an optional skb_pull, else lco_csum may trigger an overflow. The original check was

 if (csum && skb_checksum_start(skb) < skb->data) return -EINVAL;

 This had false positives when skb_checksum_start is undefined:
 when ip_summed is not CHECKSUM_PARTIAL. A discussed refinement was straightforward

 if (csum && skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_start(skb) < skb->data) return -EINVAL;

 But was eventually revised more thoroughly:
 - restrict the check to the only branch where needed, in an uncommon GRE path that uses header_ops and calls skb_pull.
 - test skb_transport_header, which is set along with csum_start in skb_partial_csum_set in the normal header_ops datapath.

 Turns out skbs can arrive in this branch without the transport header set, e.g., through BPF redirection.

 Revise the check back to check csum_start directly, and only if CHECKSUM_PARTIAL. Do leave the check in the updated location.
 Check field regardless of whether TUNNEL_CSUM is configured.

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?e62bf7fa

http://www.nessus.org/u?ccf52c49

https://nvd.nist.gov/vuln/detail/CVE-2022-49340

Plugin Details

Severity: Medium

ID: 272431

File Name: unity_linux_UTSA-2025-990149.nasl

Version: 1.1

Type: local

Published: 11/5/2025

Updated: 11/5/2025

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-2022-49340

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: 11/5/2025

Vulnerability Publication Date: 7/15/2022

Reference Information

CVE: CVE-2022-49340