CVE-2024-53066
Description
A flaw was found in the Linux kernel's NFS (Network File System) implementation. When querying file attributes, the kernel fails to properly initialize internal attribute data structures before parsing server responses. A local user can exploit this flaw by interacting with files on an NFS mount, triggering an uninitialized memory access that may lead to a kernel crash and a Denial of Service (DoS).
Mitigation
To reduce exposure on systems where NFS file sharing is not required, prevent autoloading of the NFS client kernel modules:
1. Create a configuration file in `/etc/modprobe.d/` to disable loading of the modules:
# echo "install nfs /bin/true" > /etc/modprobe.d/disable-nfs.conf
# echo "install nfsv4 /bin/true" >> /etc/modprobe.d/disable-nfs.conf
2. If the modules are currently loaded in the running kernel, attempt to unload them:
# modprobe -r nfsv4 nfs
Caveats: Blacklisting these modules prevents the system from mounting NFS shares. If filesystems are actively mounted or services are utilizing NFS, a system reboot will be required for the configuration to take effect.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.3 | 5.5 | 9.8 |
| Attack Vector | Local | Local | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | High |
| Integrity Impact | None | None | High |
| Availability Impact | Low | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory; Read Application Data
When reusing a resource such as memory or a program variable, the original contents of that resource may not be cleared before it is sent to an untrusted party.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
The uninitialized resource may contain values that cause program flow to change in ways that the programmer did not intend.
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