Linux: Buffer Copy without Checking Size of Input
CVE-2022-48696 is a high-severity buffer copy without checking size of input vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 15ff1f17847c19174b260bd7dd0de33edcebd45e, f5723cfc01932c7a8d5c78dbf7e067e537c91439 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 0.2% 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 15ff1f17847c19174b260bd7dd0de33edcebd45e or f5723cfc01932c7a8d5c78dbf7e067e537c91439, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.19.9 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | f231ff38b7b23197013b437128d196710fe282da up to, but not including, 15ff1f17847c19174b260bd7dd0de33edcebd45e; f231ff38b7b23197013b437128d196710fe282da up to, but not including, f5723cfc01932c7a8d5c78dbf7e067e537c91439; 5.16 | 15ff1f17847c19174b260bd7dd0de33edcebd45e, f5723cfc01932c7a8d5c78dbf7e067e537c91439 |
| Linux | Linux Kernel | 5.16 up to, but not including, 5.19.9; 6.0 | 5.19.9 |
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
- 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:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.1 | High | CNA |
| CVSS 3.1 | 5.5 | Medium | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: regmap: spi: Reserve space for register address/padding Currently the max_raw_read and max_raw_write limits in regmap_spi struct do not take into account the additional size of the transmitted register address and padding. This may result in exceeding the maximum permitted SPI message size, which could cause undefined behaviour, e.g. data corruption. Fix regmap_get_spi_bus() to properly adjust the above mentioned limits by reserving space for the register address/padding as set in the regmap configuration.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Buffer Copy without Checking Size of Input
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output 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.
More Buffer Copy without Checking Size of Input vulnerabilities (CWE-120)
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 Buffer Copy without Checking Size of Input vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 9.0 Critical severity
- 9.0 Critical severity
- 9.0 Critical severity
- 7.8 High severity
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