CVE-2023-52443

Aliases:UBUNTU-CVE-2023-52443DEBIAN-CVE-2023-52443
Advisory lineage Upstream: 0 Downstream: 31
Modified
Published: 22 Feb 2024, 16:13
Last modified:11 May 2026, 19:27

Vulnerability Summary

Overall Risk (default)
low
22/100
CVSS Score
5.5 MEDIUM
v3.1 (nvd)
EPSS Score
0.24% LOW
0% probability +0.22%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

22 Feb 2024, 16:13
Published
Vulnerability first disclosed
11 May 2026, 19:27
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: apparmor: avoid crash when parsed profile name is empty When processing a packed profile in unpack_profile() described like "profile :ns::samba-dcerpcd /usr/lib*/samba/{,samba/}samba-dcerpcd {...}" a string ":samba-dcerpcd" is unpacked as a fully-qualified name and then passed to aa_splitn_fqname(). aa_splitn_fqname() treats ":samba-dcerpcd" as only containing a namespace. Thus it returns NULL for tmpname, meanwhile tmpns is non-NULL. Later aa_alloc_profile() crashes as the new profile name is NULL now. general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 6 PID: 1657 Comm: apparmor_parser Not tainted 6.7.0-rc2-dirty #16 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 RIP: 0010:strlen+0x1e/0xa0 Call Trace: <TASK> ? strlen+0x1e/0xa0 aa_policy_init+0x1bb/0x230 aa_alloc_profile+0xb1/0x480 unpack_profile+0x3bc/0x4960 aa_unpack+0x309/0x15e0 aa_replace_profiles+0x213/0x33c0 policy_update+0x261/0x370 profile_replace+0x20e/0x2a0 vfs_write+0x2af/0xe00 ksys_write+0x126/0x250 do_syscall_64+0x46/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 </TASK> ---[ end trace 0000000000000000 ]--- RIP: 0010:strlen+0x1e/0xa0 It seems such behaviour of aa_splitn_fqname() is expected and checked in other places where it is called (e.g. aa_remove_profiles). Well, there is an explicit comment "a ns name without a following profile is allowed" inside. AFAICS, nothing can prevent unpacked "name" to be in form like ":samba-dcerpcd" - it is passed from userspace. Deny the whole profile set replacement in such case and inform user with EPROTO and an explaining message. Found by Linux Verification Center (linuxtesting.org).

CVSS Metrics

  • v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.24%• Percentile: 15%

Techniques & Countermeasures

  • CWE-476•NULL Pointer Dereference

    The product dereferences a pointer that it expects to be valid but is NULL.

Affected Systems

  • debian•linux

    < 5.10.209-1 | < 6.1.76-1 | < 6.6.15-1 | < 6.6.15-1

  • ubuntu•linux

    < 4.15.0-227.239 | < 5.4.0-176.196 | < 5.15.0-102.112

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    < 4.15.0-1170.183 | < 5.4.0-1122.132 | < 5.15.0-1057.63

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    < 5.15.0-1057.63~20.04.1

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    < 5.4.0-1122.132~18.04.1

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-fips

    < 4.15.0-2109.115 | all | < 5.4.0-1122.132+fips1 | < 5.15.0-1057.63+fips1

  • ubuntu•linux-aws-hwe

    < 4.15.0-1170.183~16.04.1

  • ubuntu•linux-azure

    < 4.15.0-1179.194~14.04.1 | < 4.15.0-1179.194~16.04.1 | all | < 5.4.0-1127.134 | < 5.15.0-1060.69

  • ubuntu•linux-azure-4.15

    < 4.15.0-1179.194

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    < 5.15.0-1060.69~20.04.1

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    < 5.4.0-1127.134~18.04.1

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-6.5

    < 6.5.0-1022.23~22.04.1

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fde

    all | < 5.15.0-1060.69.1 | all

  • ubuntu•linux-azure-fde-5.19

    all

  • ubuntu•linux-azure-fde-6.2

    all

  • ubuntu•linux-azure-fde-6.8

    all

  • ubuntu•linux-azure-fips

    < 4.15.0-2088.94 | all | < 5.4.0-1127.134+fips1 | < 5.15.0-1060.69+fips1

  • ubuntu•linux-bluefield

    all | < 5.4.0-1082.89 | < 5.15.0-1040.42

  • ubuntu•linux-fips

    < 4.15.0-1125.136 | all | < 5.4.0-1096.106 | < 5.15.0-102.112+fips1

  • ubuntu•linux-gcp

    < 4.15.0-1164.181~16.04.1 | all | < 5.4.0-1126.135 | < 5.15.0-1055.63

  • ubuntu•linux-gcp-4.15

    < 4.15.0-1164.181

  • ubuntu•linux-gcp-5.11

    all

  • ubuntu•linux-gcp-5.13

    all

  • ubuntu•linux-gcp-5.15

    < 5.15.0-1055.63~20.04.1

  • ubuntu•linux-gcp-5.19

    all

  • ubuntu•linux-gcp-5.3

    all

  • ubuntu•linux-gcp-5.4

    < 5.4.0-1126.135~18.04.1

  • ubuntu•linux-gcp-5.8

    all

  • ubuntu•linux-gcp-6.2

    all

  • ubuntu•linux-gcp-6.5

    < 6.5.0-1022.24~22.04.1

  • ubuntu•linux-gcp-fips

    < 4.15.0-2072.77 | all | < 5.4.0-1126.135+fips1 | < 5.15.0-1055.63+fips2

  • ubuntu•linux-gke

    all | < 5.15.0-1054.59

  • ubuntu•linux-gke-4.15

    all

  • ubuntu•linux-gke-5.15

    all

Showing first 50 affected entries in server-rendered view.

References (30)