Linux: NULL Pointer Dereference
CVE-2024-36896 is a critical-severity NULL pointer dereference vulnerability in Linux, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 5f1d68ef5ddac27c6b997adccd1c339cef1e6848, 63533549ff53d24daf47c443dbd43c308afc3434, 6119ef6517ce501fc548154691abdaf1f954a277 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.92% chance of exploitation within 30 days, higher than 61% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Linux to 5f1d68ef5ddac27c6b997adccd1c339cef1e6848 or 63533549ff53d24daf47c443dbd43c308afc3434 or 6119ef6517ce501fc548154691abdaf1f954a277 or a4b46d450c49f32e9d4247b421e58083fde304ce, whichever matches your release line, or a later version.
- Update linux_kernel to 5f1d68ef5dda or 63533549ff53 or 6119ef6517ce or a4b46d450c49, 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 |
|---|---|---|---|
| Linux | Linux | f061f43d7418cb62b8d073e221ec75d3f5b89e17 up to, but not including, 5f1d68ef5ddac27c6b997adccd1c339cef1e6848; f061f43d7418cb62b8d073e221ec75d3f5b89e17 up to, but not including, 63533549ff53d24daf47c443dbd43c308afc3434; f061f43d7418cb62b8d073e221ec75d3f5b89e17 up to, but not including, 6119ef6517ce501fc548154691abdaf1f954a277; f061f43d7418cb62b8d073e221ec75d3f5b89e17 up to, but not including, a4b46d450c49f32e9d4247b421e58083fde304ce; 6.0 | 5f1d68ef5ddac27c6b997adccd1c339cef1e6848, 63533549ff53d24daf47c443dbd43c308afc3434, 6119ef6517ce501fc548154691abdaf1f954a277, a4b46d450c49f32e9d4247b421e58083fde304ce |
| Linux | linux_kernel | f061f43d7418 up to, but not including, 5f1d68ef5dda; f061f43d7418 up to, but not including, 63533549ff53; f061f43d7418 up to, but not including, 6119ef6517ce; f061f43d7418 up to, but not including, a4b46d450c49; 6.0 | 5f1d68ef5dda, 63533549ff53, 6119ef6517ce, a4b46d450c49 |
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
- HighData or code can be modified at will.
- 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:H/A:H. Scored by CISA (ADP).
Official description
In the Linux kernel, the following vulnerability has been resolved: USB: core: Fix access violation during port device removal Testing with KASAN and syzkaller revealed a bug in port.c:disable_store(): usb_hub_to_struct_hub() can return NULL if the hub that the port belongs to is concurrently removed, but the function does not check for this possibility before dereferencing the returned value. It turns out that the first dereference is unnecessary, since hub->intfdev is the parent of the port device, so it can be changed easily. Adding a check for hub == NULL prevents further problems. The same bug exists in the disable_show() routine, and it can be fixed the same way.
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: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent NULL Pointer Dereference vulnerabilities
- 7.8 High severity
- 7.5 High severity
- 9.1 Critical severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
Spotted an error? Tell us.