---
id: CVE-1999-1021
title: >-
  NFS on SunOS 4.1 through 4.1.2 ignores the high order 16 bits in a 32 bit UID,
  which allows a local user to gain root access if the lower 16 bits are set to
  0, as fixed by the NFS jumbo patch upgrade.
summary: >-
  NFS on SunOS 4.1 through 4.1.2 ignores the high order 16 bits in a 32 bit UID,
  which allows a local user to gain root access if the lower 16 bits are set to
  0, as fixed by the NFS jumbo patch upgrade.
severity: high
cvss: 7.2
cvssVector: 'AV:L/AC:L/Au:N/C:C/I:C/A:C'
published: '1992-12-30'
updated: '2026-06-16'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-1999-1021'
references:
  - url: >-
      http://sunsolve.sun.com/pub-cgi/retrieve.pl?doctype=coll&doc=secbull/117&type=0&nav=sec.sba
    label: cve@mitre.org
  - url: 'http://www.cert.org/advisories/CA-1992-15.html'
    label: cve@mitre.org
  - url: 'http://www.securityfocus.com/bid/47'
    label: cve@mitre.org
  - url: 'https://exchange.xforce.ibmcloud.com/vulnerabilities/82'
    label: cve@mitre.org
  - url: >-
      http://sunsolve.sun.com/pub-cgi/retrieve.pl?doctype=coll&doc=secbull/117&type=0&nav=sec.sba
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'http://www.cert.org/advisories/CA-1992-15.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'http://www.securityfocus.com/bid/47'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://exchange.xforce.ibmcloud.com/vulnerabilities/82'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00411
epssPercentile: 0.32559
ingestedAt: '2026-06-19T03:39:00.711Z'
---

## Overview

NFS on SunOS 4.1 through 4.1.2 ignores the high order 16 bits in a 32 bit UID, which allows a local user to gain root access if the lower 16 bits are set to 0, as fixed by the NFS jumbo patch upgrade.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.