Red Hat Enterprise Linux 6: NULL Pointer Dereference
CVE-2023-3106 is a high-severity NULL pointer dereference vulnerability in Red Hat Enterprise Linux 6 from Red Hat, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.29% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux Kernel to 3.16.39 or 4.4.223 or 4.7.10, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| 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 |
| Linux | Linux Kernel | 3.15 up to, but not including, 3.16.39; 3.17 up to, but not including, 4.4.223; 4.5 up to, but not including, 4.7.10; 4.8 | 3.16.39, 4.4.223, 4.7.10 |
| Fedora Project | Fedora | 38 | 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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.6 | Medium | CNA (redhat.com) |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
A NULL pointer dereference vulnerability was found in netlink_dump. This issue can occur when the Netlink socket receives the message(sendmsg) for the XFRM_MSG_GETSA, XFRM_MSG_GETPOLICY type message, and the DUMP flag is set and can cause a denial of service or possibly another unspecified impact. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although it is unlikely.
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- bugzilla.redhat.com/show_bug.cgi?id=2221501Issue Tracking, Third Party Advisory
- github.com/torvalds/linux/commit/1ba5bf993c6a3142e18e68ea6452b347f9cb5635
Third-party and government advisories
- access.redhat.com/security/cve/CVE-2023-3106Third Party Advisory
Other vulnerabilities in Red Hat Enterprise Linux 6
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.9 High severity
- 7.6 High severity
- 7.5 High severity
Recent NULL Pointer Dereference vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 7.7 High severity
- 7.5 High severity
Spotted an error? Tell us.