CVE-2023-53479
Description
A flaw was found in the Linux kernel's CXL driver. This vulnerability, a use-after-free, allows a local user to cause system instability or a denial of service. The issue arises when the cxl_parse_cfmws() function attempts to use memory that has already been released. This could potentially lead to unauthorized access or control over the system.
Statement
This MODERATE impact use-after-free flaw in the Linux kernel's CXL driver. This flaw could allow a privileged attacker to crash the system or leak internal kernel information.
Mitigation
To mitigate this issue, prevent the `cxl` kernel module from loading. This can be achieved by creating a blacklist file. Create `/etc/modprobe.d/blacklist-cxl.conf` with the following content:
`blacklist cxl`
After creating the file, regenerate the initramfs and reboot the system for the changes to take effect. This may impact systems utilizing CXL devices.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.7 | 7.8 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | High | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the expired pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If the expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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