CVE-2022-50385

Description

From CVE.org

In the Linux kernel, the following vulnerability has been resolved: NFS: Fix an Oops in nfs_d_automount() When mounting from a NFSv4 referral, path->dentry can end up being a negative dentry, so derive the struct nfs_server from the dentry itself instead.

Statement

The bug in nfs_d_automount() causes a NULL-pointer dereference when handling NFSv4 referrals if the path dentry is negative. A malicious or misconfigured NFS server could trigger a client-side oops during automount, leading to a denial of service (no confidentiality/integrity impact).

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 HatNVDcve.org
Base Score5.15.55.5
Attack VectorLocalLocalLocal
Attack ComplexityHighLowLow
Privileges RequiredNoneLowLow
User InteractionNoneNoneNone
ScopeUnchangedUnchangedUnchanged
ConfidentialityNoneNoneNone
Integrity ImpactNoneNoneNone
Availability ImpactHighHighHigh

Vector

Red Hat: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

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:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Crash, Exit, or Restart

NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.

Integrity,Confidentiality

Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory

In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.

Frequently Asked Questions

Want to get errata notifications? Sign up here.