kernel: NULL Pointer Dereference
CVE-2023-32252 is a high-severity NULL pointer dereference vulnerability in kernel, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 4.06% chance of exploitation within 30 days, which is in the top 9.18% of all scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux Kernel to 5.15.145 or 6.1.29 or 6.2.16 or 6.3.2, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Kernel | kernel | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 6 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Fedora | Fedora | Not specified in the record | Not stated |
| Linux | Linux Kernel | 5.15 up to, but not including, 5.15.145; 5.16 up to, but not including, 6.1.29; 6.2 up to, but not including, 6.2.16; 6.3 up to, but not including, 6.3.2 | 5.15.145, 6.1.29, 6.2.16, 6.3.2 |
| NetApp | H300s Firmware | Not specified in the record | Not stated |
| NetApp | H500s Firmware | Not specified in the record | Not stated |
| NetApp | H700s Firmware | Not specified in the record | Not stated |
| NetApp | H410s Firmware | Not specified in the record | Not stated |
| NetApp | H410c Firmware | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | CNA (redhat.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
A flaw was found in the Linux kernel's ksmbd, a high-performance in-kernel SMB server. The specific flaw exists within the handling of SMB2_LOGOFF commands. The issue results from the lack of proper validation of a pointer prior to accessing it. An attacker can leverage this vulnerability to create a denial-of-service condition on the system.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How developers prevent this class of flaw
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Select a programming language that is not susceptible to these issues.
- Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- bugzilla.redhat.com/show_bug.cgi?id=2219815Issue Tracking, Third Party Advisory
- zerodayinitiative.com/advisories/ZDI-CAN-20590/Third Party Advisory, VDB Entry
Third-party and government advisories
- access.redhat.com/security/cve/CVE-2023-32252Third Party Advisory, VDB Entry
- security.netapp.com/advisory/ntap-20231124-0001/Third Party Advisory
Other vulnerabilities in kernel
- 7.5 High severity
- 7.8 High severity
- 8.1 High severity
- 7.1 High severity
- 8.1 High severity
- 8.1 High severity
Recent NULL Pointer Dereference vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
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