CVE-2023-52443
AppArmor: Null Pointer Dereference in Profile Unpacking Function
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).
INFO
Published Date :
Feb. 22, 2024, 5:15 p.m.
Last Modified :
June 27, 2024, 12:15 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2023-52443.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2023-52443 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2023-52443 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 27, 2024
Action Type Old Value New Value Added Reference kernel.org https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html [No types assigned] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 25, 2024
Action Type Old Value New Value Added Reference kernel.org https://lists.debian.org/debian-lts-announce/2024/06/msg00016.html [No types assigned] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Mar. 14, 2024
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://git.kernel.org/stable/c/0a12db736edbb4933e4274932aeea594b5876fa4 No Types Assigned https://git.kernel.org/stable/c/0a12db736edbb4933e4274932aeea594b5876fa4 Patch Changed Reference Type https://git.kernel.org/stable/c/1d8e62b5569cc1466ceb8a7e4872cf10160a9dcf No Types Assigned https://git.kernel.org/stable/c/1d8e62b5569cc1466ceb8a7e4872cf10160a9dcf Patch Changed Reference Type https://git.kernel.org/stable/c/55a8210c9e7d21ff2644809699765796d4bfb200 No Types Assigned https://git.kernel.org/stable/c/55a8210c9e7d21ff2644809699765796d4bfb200 Patch Changed Reference Type https://git.kernel.org/stable/c/5c0392fdafb0a2321311900be83ffa572bef8203 No Types Assigned https://git.kernel.org/stable/c/5c0392fdafb0a2321311900be83ffa572bef8203 Patch Changed Reference Type https://git.kernel.org/stable/c/5ff00408e5029d3550ee77f62dc15f1e15c47f87 No Types Assigned https://git.kernel.org/stable/c/5ff00408e5029d3550ee77f62dc15f1e15c47f87 Patch Changed Reference Type https://git.kernel.org/stable/c/77ab09b92f16c8439a948d1af489196953dc4a0e No Types Assigned https://git.kernel.org/stable/c/77ab09b92f16c8439a948d1af489196953dc4a0e Patch Changed Reference Type https://git.kernel.org/stable/c/9286ee97aa4803d99185768735011d0d65827c9e No Types Assigned https://git.kernel.org/stable/c/9286ee97aa4803d99185768735011d0d65827c9e Patch Changed Reference Type https://git.kernel.org/stable/c/9d4fa5fe2b1d56662afd14915a73b4d0783ffa45 No Types Assigned https://git.kernel.org/stable/c/9d4fa5fe2b1d56662afd14915a73b4d0783ffa45 Patch Added CWE NIST CWE-476 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions up to (excluding) 4.19.306 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.20 up to (excluding) 5.4.268 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.5.0 up to (excluding) 5.10.209 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11.0 up to (excluding) 5.15.148 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16.0 up to (excluding) 6.1.75 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2.0 up to (excluding) 6.6.14 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7.0 up to (excluding) 6.7.2 -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Feb. 22, 2024
Action Type Old Value New Value Added 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). Added Reference Linux https://git.kernel.org/stable/c/9286ee97aa4803d99185768735011d0d65827c9e [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/1d8e62b5569cc1466ceb8a7e4872cf10160a9dcf [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/5ff00408e5029d3550ee77f62dc15f1e15c47f87 [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/0a12db736edbb4933e4274932aeea594b5876fa4 [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/9d4fa5fe2b1d56662afd14915a73b4d0783ffa45 [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/5c0392fdafb0a2321311900be83ffa572bef8203 [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/77ab09b92f16c8439a948d1af489196953dc4a0e [No types assigned] Added Reference Linux https://git.kernel.org/stable/c/55a8210c9e7d21ff2644809699765796d4bfb200 [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2023-52443 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2023-52443
weaknesses.