Linux Kernel up to 6.2.9 cifs follow_automount null pointer dereference

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.0$0-$5k0.00

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.2.9 and classified as critical. This vulnerability affects the function follow_automount of the component cifs. This manipulation causes null pointer dereference. The identification of this vulnerability is CVE-2023-53246. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.2.9. Affected by this vulnerability is the function follow_automount of the component cifs. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: cifs: fix DFS traversal oops without CONFIG_CIFS_DFS_UPCALL When compiled with CONFIG_CIFS_DFS_UPCALL disabled, cifs_dfs_d_automount is NULL. cifs.ko logic for mapping CIFS_FATTR_DFS_REFERRAL attributes to S_AUTOMOUNT and corresponding dentry flags is retained regardless of CONFIG_CIFS_DFS_UPCALL, leading to a NULL pointer dereference in VFS follow_automount() when traversing a DFS referral link: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... Call Trace: <TASK> __traverse_mounts+0xb5/0x220 ? cifs_revalidate_mapping+0x65/0xc0 [cifs] step_into+0x195/0x610 ? lookup_fast+0xe2/0xf0 path_lookupat+0x64/0x140 filename_lookup+0xc2/0x140 ? __create_object+0x299/0x380 ? kmem_cache_alloc+0x119/0x220 ? user_path_at_empty+0x31/0x50 user_path_at_empty+0x31/0x50 __x64_sys_chdir+0x2a/0xd0 ? exit_to_user_mode_prepare+0xca/0x100 do_syscall_64+0x42/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc This fix adds an inline cifs_dfs_d_automount() {return -EREMOTE} handler when CONFIG_CIFS_DFS_UPCALL is disabled. An alternative would be to avoid flagging S_AUTOMOUNT, etc. without CONFIG_CIFS_DFS_UPCALL. This approach was chosen as it provides more control over the error path.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2023-53246 since 09/15/2025. The exploitation appears to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 319448 (EulerOS Virtualization 2.13.1 : kernel (EulerOS-SA-2026-2132)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.14.312, 4.19.280, 5.4.240, 5.10.177, 5.15.106, 6.1.23 or 6.2.10 eliminates this vulnerability. Applying the patch 8cd7dbc9c46d51e00a0a8372e07cc1cbb8d24a77/8afb1fabcec1929db46977e84baeee0cc0e79242/657d7c215ca974d366ab1808213f716e1e3aa950/26a32a212bc540f4773cd6af8cf73e967d72569c/b64305185b76f1d5145ce594ff48f3f0e70695bd/b7d854c33ab48e55fc233699bbefe39ec9bb5c05/1e144b68208e98fd4602c842a7149ba5f41d87fb/179a88a8558bbf42991d361595281f3e45d7edfc is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (319448) and CERT Bund (WID-SEC-2025-2053). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • IBM QRadar SIEM
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • Dell Secure Connect Gateway
  • F5 F5OS

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 5.0

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 319448
Nessus Name: EulerOS Virtualization 2.13.1 : kernel (EulerOS-SA-2026-2132)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 4.14.312/4.19.280/5.4.240/5.10.177/5.15.106/6.1.23/6.2.10
Patch: 8cd7dbc9c46d51e00a0a8372e07cc1cbb8d24a77/8afb1fabcec1929db46977e84baeee0cc0e79242/657d7c215ca974d366ab1808213f716e1e3aa950/26a32a212bc540f4773cd6af8cf73e967d72569c/b64305185b76f1d5145ce594ff48f3f0e70695bd/b7d854c33ab48e55fc233699bbefe39ec9bb5c05/1e144b68208e98fd4602c842a7149ba5f41d87fb/179a88a8558bbf42991d361595281f3e45d7edfc

Timelineinfo

09/15/2025 Advisory disclosed
09/15/2025 +0 days CVE reserved
09/15/2025 +0 days VulDB entry created
06/07/2026 +265 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2023-53246 (🔒)
GCVE (CVE): GCVE-0-2023-53246
GCVE (VulDB): GCVE-100-324019
CERT Bund: WID-SEC-2025-2053 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 09/15/2025 17:01
Updated: 06/07/2026 22:15
Changes: 09/15/2025 17:01 (59), 12/04/2025 01:42 (12), 12/29/2025 05:52 (7), 01/11/2026 07:42 (1), 06/07/2026 22:15 (2)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you want to use VulDB in your project?

Use the official API to access entries easily!