Linux Kernel up to 5.18.12 NF_STOLEN use after free

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 5.18.12. This affects an unknown part. Executing a manipulation of the argument NF_STOLEN can lead to use after free. The identification of this vulnerability is CVE-2022-49622. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 5.18.12. This vulnerability affects an unknown part. The manipulation of the argument NF_STOLEN with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: avoid skb access on nf_stolen When verdict is NF_STOLEN, the skb might have been freed. When tracing is enabled, this can result in a use-after-free: 1. access to skb->nf_trace 2. access to skb->mark 3. computation of trace id 4. dump of packet payload To avoid 1, keep a cached copy of skb->nf_trace in the trace state struct. Refresh this copy whenever verdict is != STOLEN. Avoid 2 by skipping skb->mark access if verdict is STOLEN. 3 is avoided by precomputing the trace id. Only dump the packet when verdict is not "STOLEN".

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2022-49622 since 02/26/2025. The exploitation appears to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 06/13/2025).

The vulnerability scanner Nessus provides a plugin with the ID 238183 (EulerOS 2.0 SP12 : kernel (EulerOS-SA-2025-1590)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.18.13 eliminates this vulnerability. Applying the patch 0016d5d46d7440729a3132f61a8da3bf7f84e2ba/e34b9ed96ce3b06c79bf884009b16961ca478f87 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (238183). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.18.0
• 5.18.1
• 5.18.2
• 5.18.3
• 5.18.4
• 5.18.5
• 5.18.6
• 5.18.7
• 5.18.8
• 5.18.9
• 5.18.10
• 5.18.11
• 5.18.12

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion