Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Local
0

CVE-2024-46795

Disclosure Date: September 18, 2024 •
CVE-2024-46795 CVSS v3 Base Score: 5.5
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: unset the binding mark of a reused connection

Steve French reported null pointer dereference error from sha256 lib.
cifs.ko can send session setup requests on reused connection.
If reused connection is used for binding session, conn->binding can
still remain true and generate_preauth_hash() will not set
sess->Preauth_HashValue and it will be NULL.
It is used as a material to create an encryption key in
ksmbd_gen_smb311_encryptionkey. –>Preauth_HashValue cause null pointer
dereference error from crypto_shash_update().

BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) – not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 8 PID: 429254 Comm: kworker/8:39
Hardware name: LENOVO 20MAS08500/20MAS08500, BIOS N2CET69W (1.52 )
Workqueue: ksmbd-io handle_ksmbd_work [ksmbd]
RIP: 0010:lib_sha256_base_do_update.isra.0+0x11e/0x1d0 [sha256_ssse3]
<TASK>
? show_regs+0x6d/0x80
? __die+0x24/0x80
? page_fault_oops+0x99/0x1b0
? do_user_addr_fault+0x2ee/0x6b0
? exc_page_fault+0x83/0x1b0
? asm_exc_page_fault+0x27/0x30
? __pfx_sha256_transform_rorx+0x10/0x10 [sha256_ssse3]
? lib_sha256_base_do_update.isra.0+0x11e/0x1d0 [sha256_ssse3]
? __pfx_sha256_transform_rorx+0x10/0x10 [sha256_ssse3]
? __pfx_sha256_transform_rorx+0x10/0x10 [sha256_ssse3]
_sha256_update+0x77/0xa0 [sha256_ssse3]
sha256_avx2_update+0x15/0x30 [sha256_ssse3]
crypto_shash_update+0x1e/0x40
hmac_update+0x12/0x20
crypto_shash_update+0x1e/0x40
generate_key+0x234/0x380 [ksmbd]
generate_smb3encryptionkey+0x40/0x1c0 [ksmbd]
ksmbd_gen_smb311_encryptionkey+0x72/0xa0 [ksmbd]
ntlm_authenticate.isra.0+0x423/0x5d0 [ksmbd]
smb2_sess_setup+0x952/0xaa0 [ksmbd]
__process_request+0xa3/0x1d0 [ksmbd]
__handle_ksmbd_work+0x1c4/0x2f0 [ksmbd]
handle_ksmbd_work+0x2d/0xa0 [ksmbd]
process_one_work+0x16c/0x350
worker_thread+0x306/0x440
? __pfx_worker_thread+0x10/0x10
kthread+0xef/0x120
? __pfx_kthread+0x10/0x10
ret_from_fork+0x44/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>

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CVSS V3 Severity and Metrics
Base Score:
5.5 Medium
Impact Score:
3.6
Exploitability Score:
1.8
Vector:
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector (AV):
Local
Attack Complexity (AC):
Low
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
None
Integrity (I):
None
Availability (A):
High

General Information

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
Linux 9914f1bd61d5
Linux not down converted
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown

Vendors

  • linux

Products

  • linux kernel,
  • linux kernel 6.11
Technical Analysis