Linux: NULL Pointer Dereference
CVE-2023-52696 is a high-severity NULL pointer dereference vulnerability in Linux, 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. The record lists versions 9da4a56dd3772570512ca58aa8832b052ae910dc, a67a04ad05acb56640798625e73fa54d6d41cce1, 6b58d16037217d0c64a2a09b655f370403ec7219 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 0.82% chance of exploitation within 30 days, higher than 58% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 9da4a56dd3772570512ca58aa8832b052ae910dc or a67a04ad05acb56640798625e73fa54d6d41cce1 or 6b58d16037217d0c64a2a09b655f370403ec7219 or f152a6bfd187f67afeffc9fd68cbe46f51439be0, whichever matches your release line, or a later version.
- Update linux_kernel to e123015c0ba8 or 9da4a56dd377 or a67a04ad05ac or 6b58d1603721, 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 | b9ef7b4b867f56114bedbe6bf104cfaba0ca818e up to, but not including, 9da4a56dd3772570512ca58aa8832b052ae910dc; b9ef7b4b867f56114bedbe6bf104cfaba0ca818e up to, but not including, a67a04ad05acb56640798625e73fa54d6d41cce1; b9ef7b4b867f56114bedbe6bf104cfaba0ca818e up to, but not including, 6b58d16037217d0c64a2a09b655f370403ec7219; b9ef7b4b867f56114bedbe6bf104cfaba0ca818e up to, but not including, f152a6bfd187f67afeffc9fd68cbe46f51439be0; b9ef7b4b867f56114bedbe6bf104cfaba0ca818e up to, but not including, 69f95c5e9220f77ce7c540686b056c2b49e9a664; b9ef7b4b867f56114bedbe6bf104cfaba0ca818e up to, but not including, b02ecc35d01a76b4235e008d2dd292895b28ecab; b9ef7b4b867f56114bedbe6bf104cfaba0ca818e up to, but not including, e123015c0ba859cf48aa7f89c5016cc6e98e018d; 4.20 | 9da4a56dd3772570512ca58aa8832b052ae910dc, a67a04ad05acb56640798625e73fa54d6d41cce1, 6b58d16037217d0c64a2a09b655f370403ec7219, f152a6bfd187f67afeffc9fd68cbe46f51439be0, 69f95c5e9220f77ce7c540686b056c2b49e9a664, b02ecc35d01a76b4235e008d2dd292895b28ecab |
| Linux | linux_kernel | b9ef7b4b867f up to, but not including, e123015c0ba8; b9ef7b4b867f up to, but not including, 9da4a56dd377; b9ef7b4b867f up to, but not including, a67a04ad05ac; b9ef7b4b867f up to, but not including, 6b58d1603721; b9ef7b4b867f up to, but not including, f152a6bfd187; b9ef7b4b867f up to, but not including, 69f95c5e9220; b9ef7b4b867f up to, but not including, b02ecc35d01a; 4.2.0 | e123015c0ba8, 9da4a56dd377, a67a04ad05ac, 6b58d1603721, f152a6bfd187, 69f95c5e9220 |
| Debian | Debian Linux | 10.0 | 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 CISA (ADP).
Official description
In the Linux kernel, the following vulnerability has been resolved: powerpc/powernv: Add a null pointer check in opal_powercap_init() kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure.
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
- git.kernel.org/stable/c/69f95c5e9220f77ce7c540686b056c2b49e9a664
- git.kernel.org/stable/c/6b58d16037217d0c64a2a09b655f370403ec7219
- git.kernel.org/stable/c/9da4a56dd3772570512ca58aa8832b052ae910dc
- git.kernel.org/stable/c/a67a04ad05acb56640798625e73fa54d6d41cce1
- git.kernel.org/stable/c/b02ecc35d01a76b4235e008d2dd292895b28ecab
- git.kernel.org/stable/c/e123015c0ba859cf48aa7f89c5016cc6e98e018d
- git.kernel.org/stable/c/f152a6bfd187f67afeffc9fd68cbe46f51439be0
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2024/06/msg00016.htmlMailing List, Third Party Advisory
Recent NULL Pointer Dereference vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
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