Linux: Out-of-bounds Write
CVE-2022-48927 is a high-severity out-of-bounds write 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 0cb9b2f73c182d242a640e512f4785c7c504512f, 082d2c047b0d305bb0b6e9f9d671a09470e2db2d, b7a78a8adaa8849c02f174d707aead0f85dca0da 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 0.22% 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 0cb9b2f73c182d242a640e512f4785c7c504512f or 082d2c047b0d305bb0b6e9f9d671a09470e2db2d or b7a78a8adaa8849c02f174d707aead0f85dca0da, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.26 or 5.16.12, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 9374e8f5a38defe90bc65b2decf317c1c62d91dd up to, but not including, 0cb9b2f73c182d242a640e512f4785c7c504512f; 9374e8f5a38defe90bc65b2decf317c1c62d91dd up to, but not including, 082d2c047b0d305bb0b6e9f9d671a09470e2db2d; 9374e8f5a38defe90bc65b2decf317c1c62d91dd up to, but not including, b7a78a8adaa8849c02f174d707aead0f85dca0da; 5.14 | 0cb9b2f73c182d242a640e512f4785c7c504512f, 082d2c047b0d305bb0b6e9f9d671a09470e2db2d, b7a78a8adaa8849c02f174d707aead0f85dca0da |
| Linux | Linux Kernel | 5.14 up to, but not including, 5.15.26; 5.16 up to, but not including, 5.16.12 | 5.15.26, 5.16.12 |
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: iio: adc: tsc2046: fix memory corruption by preventing array overflow On one side we have indio_dev->num_channels includes all physical channels + timestamp channel. On other side we have an array allocated only for physical channels. So, fix memory corruption by ARRAY_SIZE() instead of num_channels variable. Note the first case is a cleanup rather than a fix as the software timestamp channel bit in active_scanmask is never set by the IIO core.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
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 Write vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.8 High severity
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