Linux: Out-of-bounds Read
CVE-2023-52731 is a high-severity out-of-bounds read vulnerability in Linux, 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. The record lists versions 87b9802ca824fcee7915e717e9a60471af62e8e9, f1d91f0e9d5a240a809698d7d9c5a538e7dcc149, 3efc61d95259956db25347e2a9562c3e54546e20 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 0.25% 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 to 87b9802ca824fcee7915e717e9a60471af62e8e9 or f1d91f0e9d5a240a809698d7d9c5a538e7dcc149 or 3efc61d95259956db25347e2a9562c3e54546e20, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.13 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 186b89659c4c67cccead52961eab0ca3b23951dc up to, but not including, 87b9802ca824fcee7915e717e9a60471af62e8e9; 56c134f7f1b58be08bdb0ca8372474a4a5165f31 up to, but not including, f1d91f0e9d5a240a809698d7d9c5a538e7dcc149; 56c134f7f1b58be08bdb0ca8372474a4a5165f31 up to, but not including, 3efc61d95259956db25347e2a9562c3e54546e20; 5.19 | 87b9802ca824fcee7915e717e9a60471af62e8e9, f1d91f0e9d5a240a809698d7d9c5a538e7dcc149, 3efc61d95259956db25347e2a9562c3e54546e20 |
| Linux | Linux Kernel | 5.19 up to, but not including, 6.1.13; 6.2 | 6.1.13 |
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 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: fbdev: Fix invalid page access after closing deferred I/O devices When a fbdev with deferred I/O is once opened and closed, the dirty pages still remain queued in the pageref list, and eventually later those may be processed in the delayed work. This may lead to a corruption of pages, hitting an Oops. This patch makes sure to cancel the delayed work and clean up the pageref list at closing the device for addressing the bug. A part of the cleanup code is factored out as a new helper function that is called from the common fb_release().
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
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
Recent Out-of-bounds Read vulnerabilities
- 7.8 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
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