Linux Kernel: Out-of-bounds Read
CVE-2022-47940 is a high-severity out-of-bounds read vulnerability in Linux Kernel from Linux, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 5.15.145, 5.18.18 as the first without the flaw, so updating Linux Kernel to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.54% chance of exploitation within 30 days, higher than 75% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux Kernel to 5.15.145 or 5.18.18, whichever matches your release line, or a later version.
- Read the advisory on cdn.kernel.org for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux Kernel | 5.15 up to, but not including, 5.15.145; 5.16 up to, but not including, 5.18.18 | 5.15.145, 5.18.18 |
Version data comes from NVD's product matching. 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
- 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:N/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 | 8.1 | High | NVD |
| CVSS 3.1 | 8.1 | High | CISA (ADP) |
Official description
An issue was discovered in ksmbd in the Linux kernel 5.15 through 5.18 before 5.18.18. fs/ksmbd/smb2pdu.c lacks length validation in the non-padding case in smb2_write.
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
Advisories
Patches and release notes
- github.com/torvalds/linux/commit/158a66b245739e15858de42c0ba60fcf3de9b8e6Third Party Advisory
Third-party and government advisories
- openwall.com/lists/oss-security/2022/12/23/10Mailing List, Third Party Advisory
Other vulnerabilities in Linux Kernel
- 9.8 Critical severity
- 7.0 High severity
- 7.8 High severity
- 7.1 High severity
- 7.0 High severity
- 7.8 High severity
Recent Out-of-bounds Read vulnerabilities
- 9.1 Critical severity
- 8.1 High severity
- 9.8 Critical severity
- 7.5 High severity
- 8.1 High severity
- 9.1 Critical severity
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