CVE-2023-52620

What it actually does

The vulnerability permits configuration of timeout parameters on anonymous sets within the nf_tables subsystem of the Linux kernel netfilter framework, which were never intended for userspace interaction, resulting in improper input validation that can lead to limited availability impact under specific local conditions.

Why it matters to the business

Organizations running affected Linux kernel versions face low-risk potential for minor network filtering disruptions that require patching to restore full stability, with no associated ransomware campaigns or high-value threat actor activity increasing urgency.

How an attack unfolds

An attacker with local low-privileged access attempts to supply disallowed timeout parameters when interacting with nf_tables anonymous sets through userspace interfaces, triggering the validation flaw to produce limited denial-of-service effects on network operations.

How to fix it

Upgrade the Linux kernel to a fixed commit such as 116b0e8e4673a5faa8a739a19b467010c4d3058c or apply package updates such as gssdp 1.0.5-1.el8 and gupnp-devel 1.0.6-1.el8 where those components are present.

How to confirm the fix worked

Confirm the running kernel or relevant packages report versions at or above the listed fixes, then exercise nf_tables set creation paths to verify timeout parameters are rejected on anonymous sets.

Typical attack path

1. Obtain local access on a vulnerable Linux system
2. Craft nf_tables operations targeting anonymous sets with timeout parameters
3. Trigger improper validation to induce availability impact

How to detect it

Review kernel and netfilter logs for validation errors involving set timeouts or anonymous sets, and inventory kernel versions across the environment to identify unpatched systems.

What your security team should do

• Apply kernel and package updates to the specified fixed versions as soon as possible
• Audit local netfilter configurations to remove any reliance on anonymous sets
• Monitor kernel update channels for downstream dependent package rebuilds