5.5

CVE-2024-46795: ksmbd: unset the binding mark of a reused connection

Modified
AliasesUBUNTU-CVE-2024-46795DEBIAN-CVE-2024-46795
Published 18-09-2024Last modified 11-05-2026

Vulnerability summary

CVE-2024-46795 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 19.8% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.27%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 14 · Related 10
DLA-4008-1DSA-5782-1MGASA-2024-0316MGASA-2024-0318USN-7100-1USN-7100-2

Timeline

  1. 18-09-2024
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

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>

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.27%

Chance of exploitation in the next 30 days

Percentile

20%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.27% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu117 products
  • linux< 5.15.0-125.135 | < 6.8.0-50.51
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.15.0-1072.78 | < 6.8.0-1020.22
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ f5a544e3bab78142207e0242d22442db85ba1eff, < 9914f1bd61d5e838bb1ab15a71076d37a6db65d1 | ≥ f5a544e3bab78142207e0242d22442db85ba1eff, < 93d54a4b59c4b3d803d20aa645ab5ca71f3b3b02 | ≥ f5a544e3bab78142207e0242d22442db85ba1eff, < 41bc256da7e47b679df87c7fc7a5b393052b9cce | ≥ f5a544e3bab78142207e0242d22442db85ba1eff, < 4c8496f44f5bb5c06cdef5eb130ab259643392a1 | ≥ f5a544e3bab78142207e0242d22442db85ba1eff, < 78c5a6f1f630172b19af4912e755e1da93ef0ab5 | 5.15
  • linux_kernel≥ 5.15, < 5.15.167 | ≥ 5.16, < 6.1.110 | ≥ 6.2, < 6.6.51 | ≥ 6.7, < 6.10.10 | 6.11:rc1 | 6.11:rc2 | 6.11:rc3 | 6.11:rc4 | 6.11:rc5 | 6.11:rc6
Debian1 product
  • linux< 6.1.112-1 | < 6.10.11-1

3 vendors · 120 products

References

21 links
Show all 21 references