Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2023-52751: smb: client: fix use-after-free in smb2_query_info_compound()

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.24% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 06c106e1e8568e840c946cc0222579e3d29dab8e, 5c86919455c1edec99ebd3338ad213b59271a71b, 6db94d08359c43f2c8fe372811cdee04564a41b9; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 06c106e1e8568e840c946cc0222579e3d29dab8e, 5c86919455c1edec99ebd3338ad213b59271a71b, 6db94d08359c43f2c8fe372811cdee04564a41b9; cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-after-free in smb2_query_info_compound() The following UAF was triggered when running fstests generic/072 with KASAN enabled against Windows Server 2022 and mount options 'multichannel,max_channels=2,vers=3.1.1,mfsymlinks,noperm' BUG: KASAN: slab-use-after-free in smb2_query_info_compound+0x423/0x6d0 [cifs] Read of size 8 at addr ffff888014941048 by task xfs_io/27534 CPU: 0 PID: 27534 Comm: xfs_io Not tainted 6.6.0-rc7 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack_lvl+0x4a/0x80 print_report+0xcf/0x650 ? srso_alias_return_thunk+0x5/0x7f ? srso_alias_return_thunk+0x5/0x7f ? __phys_addr+0x46/0x90 kasan_report+0xda/0x110 ? smb2_query_info_compound+0x423/0x6d0 [cifs] ? smb2_query_info_compound+0x423/0x6d0 [cifs] smb2_query_info_compound+0x423/0x6d0 [cifs] ? __pfx_smb2_query_info_compound+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0x7f ? __stack_depot_save+0x39/0x480 ? kasan_save_stack+0x33/0x60 ? kasan_set_track+0x25/0x30 ? ____kasan_slab_free+0x126/0x170 smb2_queryfs+0xc2/0x2c0 [cifs] ? __pfx_smb2_queryfs+0x10/0x10 [cifs] ? __pfx___lock_acquire+0x10/0x10 smb311_queryfs+0x210/0x220 [cifs] ? __pfx_smb311_queryfs+0x10/0x10 [cifs] ? srso_alias_return_thunk+0x5/0x7f ? __lock_acquire+0x480/0x26c0 ? lock_release+0x1ed/0x640 ? srso_alias_return_thunk+0x5/0x7f ? do_raw_spin_unlock+0x9b/0x100 cifs_statfs+0x18c/0x4b0 [cifs] statfs_by_dentry+0x9b/0xf0 fd_statfs+0x4e/0xb0 __do_sys_fstatfs+0x7f/0xe0 ? __pfx___do_sys_fstatfs+0x10/0x10 ? srso_alias_return_thunk+0x5/0x7f ? lockdep_hardirqs_on_prepare+0x136/0x200 ? srso_alias_return_thunk+0x5/0x7f do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Allocated by task 27534: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 __kasan_kmalloc+0x8f/0xa0 open_cached_dir+0x71b/0x1240 [cifs] smb2_query_info_compound+0x5c3/0x6d0 [cifs] smb2_queryfs+0xc2/0x2c0 [cifs] smb311_queryfs+0x210/0x220 [cifs] cifs_statfs+0x18c/0x4b0 [cifs] statfs_by_dentry+0x9b/0xf0 fd_statfs+0x4e/0xb0 __do_sys_fstatfs+0x7f/0xe0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Freed by task 27534: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 kasan_save_free_info+0x2b/0x50 ____kasan_slab_free+0x126/0x170 slab_free_freelist_hook+0xd0/0x1e0 __kmem_cache_free+0x9d/0x1b0 open_cached_dir+0xff5/0x1240 [cifs] smb2_query_info_compound+0x5c3/0x6d0 [cifs] smb2_queryfs+0xc2/0x2c0 [cifs] This is a race between open_cached_dir() and cached_dir_lease_break() where the cache entry for the open directory handle receives a lease break while creating it. And before returning from open_cached_dir(), we put the last reference of the new @cfid because of !@cfid->has_lease. Besides the UAF, while running xfstests a lot of missed lease breaks have been noticed in tests that run several concurrent statfs(2) calls on those cached fids CIFS: VFS: \\w22-root1.gandalf.test No task to wake, unknown frame... CIFS: VFS: \\w22-root1.gandalf.test Cmd: 18 Err: 0x0 Flags: 0x1... CIFS: VFS: \\w22-root1.gandalf.test smb buf 00000000715bfe83 len 108 CIFS: VFS: Dump pending requests: CIFS: VFS: \\w22-root1.gandalf.test No task to wake, unknown frame... CIFS: VFS: \\w22-root1.gandalf.test Cmd: 18 Err: 0x0 Flags: 0x1... CIFS: VFS: \\w22-root1.gandalf.test smb buf 000000005aa7316e len 108 ... To fix both, in open_cached_dir() ensure that @cfid->has_lease is set right before sending out compounded request so that any potential lease break will be get processed by demultiplex thread while we're still caching @cfid. And, if open failed for some reason, re-check @cfid->has_lease to decide whether or not put lease reference.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
May 21, 2024
Updated
Oct 30, 2026
EPSS
0.2% · 15th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.8
CNA · Linux
7.8
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-52751

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernelbefore 6.5.13
  • linux linux kernel6.6 and later · before 6.6.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.1affected
    • ebe98f1447bbccf8228335c62d86af02a0ed23f7 and later · before 06c106e1e8568e840c946cc0222579e3d29dab8eaffected · git
    • ebe98f1447bbccf8228335c62d86af02a0ed23f7 and later · before 6db94d08359c43f2c8fe372811cdee04564a41b9affected · git
    • ebe98f1447bbccf8228335c62d86af02a0ed23f7 and later · before 93877b9afc2994c89362007aac480a7b150f386faffected · git
    • ebe98f1447bbccf8228335c62d86af02a0ed23f7 and later · before 5c86919455c1edec99ebd3338ad213b59271a71baffected · git
    • before 6.1not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.5.13 and later · up to and including 6.5.*not affected · semver
    • 6.6.3 and later · up to and including 6.6.*not affected · semver
    • 6.7 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.5.13-16.5.13-1
openSUSE:Leap 15.6dtb-aarch64before 6.4.0-150600.23.17.16.4.0-150600.23.17.1
openSUSE:Leap 15.6kernel-64kbbefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
openSUSE:Leap 15.6kernel-azurebefore 6.4.0-150600.8.8.26.4.0-150600.8.8.2
openSUSE:Leap 15.6kernel-debugbefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
openSUSE:Leap 15.6kernel-defaultbefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
openSUSE:Leap 15.6kernel-default-basebefore 6.4.0-150600.23.17.1.150600.12.6.26.4.0-150600.23.17.1.150600.12.6.2
openSUSE:Leap 15.6kernel-docsbefore 6.4.0-150600.23.17.36.4.0-150600.23.17.3
openSUSE:Leap 15.6kernel-kvmsmallbefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
openSUSE:Leap 15.6kernel-obs-buildbefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
openSUSE:Leap 15.6kernel-obs-qabefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
openSUSE:Leap 15.6kernel-sourcebefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
openSUSE:Leap 15.6kernel-source-azurebefore 6.4.0-150600.8.8.26.4.0-150600.8.8.2
openSUSE:Leap 15.6kernel-symsbefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
openSUSE:Leap 15.6kernel-syms-azurebefore 6.4.0-150600.8.8.16.4.0-150600.8.8.1
openSUSE:Leap 15.6kernel-zfcpdumpbefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
SUSE:Linux Enterprise Live Patching 15 SP6kernel-livepatch-SLE15-SP6_Update_3before 1-150600.13.3.11-150600.13.3.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6kernel-64kbbefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6kernel-defaultbefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6kernel-default-basebefore 6.4.0-150600.23.17.1.150600.12.6.26.4.0-150600.23.17.1.150600.12.6.2
SUSE:Linux Enterprise Module for Basesystem 15 SP6kernel-sourcebefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6kernel-zfcpdumpbefore 6.4.0-150600.23.17.16.4.0-150600.23.17.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6kernel-docsbefore 6.4.0-150600.23.17.36.4.0-150600.23.17.3

+5

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2023-52879May 21, 2024 · tracing: Have trace_event_file have ref counters
    22Monitor
  • ← EarlierCVE-2021-47316May 21, 2024 · nfsd: fix NULL dereference in nfs3svc_encode_getaclres
    22Monitor
  • Later →CVE-2023-52761May 21, 2024 · riscv: VMAP_STACK overflow detection thread-safe
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux06c106e1e8568e840c946cc0222579e3d29dab8eVendor (CNA)
Linux Linux5c86919455c1edec99ebd3338ad213b59271a71bVendor (CNA)
Linux Linux6db94d08359c43f2c8fe372811cdee04564a41b9Vendor (CNA)
Linux Linux93877b9afc2994c89362007aac480a7b150f386fVendor (CNA)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0Release NotesMicrosoft (MSRC)
debian:linux6.5.13-1 · Debian:13Package registry (OSV)
opensuse:dtb-aarch646.4.0-150600.23.17.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-64kb6.4.0-150600.23.17.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-debug6.4.0-150600.23.17.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-default6.4.0-150600.23.17.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-default-base6.4.0-150600.23.17.1.150600.12.6.2 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-docs6.4.0-150600.23.17.3 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-kvmsmall6.4.0-150600.23.17.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-obs-build6.4.0-150600.23.17.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-obs-qa6.4.0-150600.23.17.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-source6.4.0-150600.23.17.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-syms6.4.0-150600.23.17.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-zfcpdump6.4.0-150600.23.17.1 · openSUSE:Leap 15.6Package registry (OSV)
suse:kernel-64kb6.4.0-150600.23.17.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)
suse:kernel-azure6.4.0-150600.8.8.2 · SUSE:Linux Enterprise Module for Public Cloud 15 SP6Package registry (OSV)
suse:kernel-default6.4.0-150600.23.17.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)
suse:kernel-default-base6.4.0-150600.23.17.1.150600.12.6.2 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)
suse:kernel-docs6.4.0-150600.23.17.3 · SUSE:Linux Enterprise Module for Development Tools 15 SP6Package registry (OSV)
suse:kernel-livepatch-SLE15-SP6_Update_31-150600.13.3.1 · SUSE:Linux Enterprise Live Patching 15 SP6Package registry (OSV)
suse:kernel-obs-build6.4.0-150600.23.17.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP6Package registry (OSV)
suse:kernel-source6.4.0-150600.23.17.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)
suse:kernel-source-azure6.4.0-150600.8.8.2 · SUSE:Linux Enterprise Module for Public Cloud 15 SP6Package registry (OSV)
suse:kernel-syms6.4.0-150600.23.17.1 · SUSE:Linux Enterprise Module for Development Tools 15 SP6Package registry (OSV)
suse:kernel-syms-azure6.4.0-150600.8.8.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP6Package registry (OSV)
suse:kernel-zfcpdump6.4.0-150600.23.17.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP6Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records