Linux: Out-of-bounds Read
CVE-2022-50394 is a high-severity out-of-bounds read 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 4a7bb1d93addb2f67e36fed00a53cb7f270d7b7a, 03b7ef7a6c5ca1ff553470166b4919db88b810f6, bfe41d966c860a8ad4c735639d616da270c92735 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 0.17% 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 4a7bb1d93addb2f67e36fed00a53cb7f270d7b7a or 03b7ef7a6c5ca1ff553470166b4919db88b810f6 or bfe41d966c860a8ad4c735639d616da270c92735 or cdcbae2c5003747ddfd14e29db9c1d5d7e7c44dd, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.9.337 or 4.14.303 or 4.19.270 or 5.4.229, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9 up to, but not including, 4a7bb1d93addb2f67e36fed00a53cb7f270d7b7a; 13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9 up to, but not including, 03b7ef7a6c5ca1ff553470166b4919db88b810f6; 13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9 up to, but not including, bfe41d966c860a8ad4c735639d616da270c92735; 13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9 up to, but not including, cdcbae2c5003747ddfd14e29db9c1d5d7e7c44dd; 13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9 up to, but not including, 9ac541a0898e8ec187a3fa7024b9701cffae6bf2; 13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9 up to, but not including, 96c12fd0ec74641295e1c3c34dea3dce1b6c3422; 13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9 up to, but not including, a642469d464b2780a25a49b51ae56623c65eac34; 13f35ac14cd0a9a1c4f0034c4c40d0ae98844ce9 up to, but not including, 233348a04becf133283f0076e20b317302de21d9; and 2 more ranges | 4a7bb1d93addb2f67e36fed00a53cb7f270d7b7a, 03b7ef7a6c5ca1ff553470166b4919db88b810f6, bfe41d966c860a8ad4c735639d616da270c92735, cdcbae2c5003747ddfd14e29db9c1d5d7e7c44dd, 9ac541a0898e8ec187a3fa7024b9701cffae6bf2, 96c12fd0ec74641295e1c3c34dea3dce1b6c3422 |
| Linux | Linux Kernel | 3.9 up to, but not including, 4.9.337; 4.10 up to, but not including, 4.14.303; 4.15 up to, but not including, 4.19.270; 4.20 up to, but not including, 5.4.229; 5.5 up to, but not including, 5.10.163; 5.11 up to, but not including, 5.15.86; 5.16 up to, but not including, 6.0.16; 6.1 up to, but not including, 6.1.2 | 4.9.337, 4.14.303, 4.19.270, 5.4.229, 5.10.163, 5.15.86 |
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
- NoneNothing can be modified.
- 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:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.1 | High | NVD |
| CVSS 3.1 | 7.1 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: i2c: ismt: Fix an out-of-bounds bug in ismt_access() When the driver does not check the data from the user, the variable 'data->block[0]' may be very large to cause an out-of-bounds bug. The following log can reveal it: [ 33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20 [ 33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA: WRITE [ 33.996475] ================================================================== [ 33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b [ 33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485 [ 33.999450] Call Trace: [ 34.001849] memcpy+0x20/0x60 [ 34.002077] ismt_access.cold+0x374/0x214b [ 34.003382] __i2c_smbus_xfer+0x44f/0xfb0 [ 34.004007] i2c_smbus_xfer+0x10a/0x390 [ 34.004291] i2cdev_ioctl_smbus+0x2c8/0x710 [ 34.005196] i2cdev_ioctl+0x5ec/0x74c Fix this bug by checking the size of 'data->block[0]' first.
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
- git.kernel.org/stable/c/03b7ef7a6c5ca1ff553470166b4919db88b810f6
- git.kernel.org/stable/c/233348a04becf133283f0076e20b317302de21d9
- git.kernel.org/stable/c/39244cc754829bf707dccd12e2ce37510f5b1f8d
- git.kernel.org/stable/c/4a7bb1d93addb2f67e36fed00a53cb7f270d7b7a
- git.kernel.org/stable/c/96c12fd0ec74641295e1c3c34dea3dce1b6c3422
- git.kernel.org/stable/c/9ac541a0898e8ec187a3fa7024b9701cffae6bf2
- git.kernel.org/stable/c/a642469d464b2780a25a49b51ae56623c65eac34
- git.kernel.org/stable/c/bfe41d966c860a8ad4c735639d616da270c92735
- git.kernel.org/stable/c/cdcbae2c5003747ddfd14e29db9c1d5d7e7c44dd
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.1 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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