Privilege escalation in Linux kernel netfilter

1) Use-after-free

EUVDB-ID: #VU64668

Risk: Low

CVSSv3.1: 7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2022-32250

CWE-ID: CWE-416 - Use After Free

Exploit availability: Yes

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free incorrect NFT_STATEFUL_EXPR in net/netfilter/nf_tables_api.c in Linux kernel. A local user with ability to create user/net namespaces can execute arbitrary code with root privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.18 - 5.18.1

External links

http://www.openwall.com/lists/oss-security/2022/05/31/1
http://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/net/netfilter?id=520778042ccca019f3ffa136dd0ca565c486cedd
http://www.openwall.com/lists/oss-security/2022/06/03/1
http://www.openwall.com/lists/oss-security/2022/06/04/1
http://www.debian.org/security/2022/dsa-5161
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UIZTJOJCVVEJVOQSCHE6IJQKMPISHQ5L/
http://bugzilla.redhat.com/show_bug.cgi?id=2092427
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MO6Y3TC4WUUNKRP7OQA26OVTZTPCS6F2/
http://www.openwall.com/lists/oss-security/2022/06/20/1
http://www.zerodayinitiative.com/advisories/ZDI-23-1834/

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.