PT-2022-5973 · Linux+2 · Linux Kernel+2

Arnaud Gatignol + 4 · Published 2022-08-18 · Updated 2023-07-11 · CVE-2022-47939

Positive Technologies (AI Summary)

CVSS v2.0

10

Critical

Base vector

AV:N/AC:L/Au:N/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions Linux kernel versions 5.15 through 5.19 before 5.19.2

Description A use-after-free issue exists in the Linux kernel's ksmbd module, specifically in the fs/ksmbd/smb2pdu.c file, related to the SMB2 TREE DISCONNECT command. This issue can be exploited by a remote attacker to execute arbitrary code on vulnerable Linux kernel versions. The ksmbd server, which implements the SMB3 protocol in the kernel for network file sharing, is affected when it handles SMB2 TREE DISCONNECT commands without properly checking the existence of an object before performing operations on it.

Recommendations For Linux kernel versions 5.15 through 5.19 before 5.19.2, update to version 5.19.2 or later to resolve the issue. As a temporary workaround, consider disabling the ksmbd server until a patch is available. Restrict access to the SMB2 TREE DISCONNECT command to minimize the risk of exploitation.

Fix

Use After Free

Weakness Enumeration

CWE-416

Related Identifiers

ALT-PU-2022-2453

ALT-PU-2022-2454

ALT-PU-2022-2474

ALT-PU-2022-2497

ALT-PU-2022-2682

ALT-PU-2022-2692

ALT-PU-2022-2915

ALT-PU-2022-2919

AZL-12094

BDU:2022-07401

CVE-2022-47939

OESA-2023-1012

ROSA-SA-2023-2189

ZDI-22-1690

Affected Products

Alt Linux

Astra Linux

Linux Kernel

References · 37

• https://github.com/torvalds/linux/commit/cf6531d98190fa2cf92a6d8bbc8af0a4740a223c · Patch
• https://cve.org/CVERecord?id=CVE-2022-47939 · Security Note
• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=cf6531d98190fa2cf92a6d8bbc8af0a4740a223c · Vendor Advisory
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.19.2 · Vendor Advisory
• https://osv.dev/vulnerability/AZL-12094 · Vendor Advisory
• https://osv.dev/vulnerability/OESA-2023-1012 · Vendor Advisory
• https://ubuntu.com/security/CVE-2022-47939 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2022-47939 · Security Note
• https://zerodayinitiative.com/advisories/ZDI-22-1690 · Security Note
• https://osv.dev/vulnerability/CVE-2022-47939 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2022-47939 · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se16-bulletin-20231214SE16 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2022-47938 · Security Note
• https://wiki.astralinux.ru/astra-linux-se17-bulletin-2023-0303SE17MD · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2022-47939 · Vendor Advisory