---
id: CVE-2021-3998
title: A flaw was found in glibc
summary: >-
  A flaw was found in glibc. The realpath() function can mistakenly return an
  unexpected value, potentially leading to information leakage and disclosure of
  sensitive data.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-125
  - CWE-252
vendor: gnu
product: glibc
affected:
  - 'glibc >= 2.33, < 2.35'
  - ontap_select_deploy_administration_utility
  - h300s_firmware
  - h500s_firmware
  - h700s_firmware
  - h410s_firmware
  - h410c_firmware
patched:
  - glibc 2.35
published: '2022-08-24'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T10:17:49.647'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-3998'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2021-3998'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2024633'
    label: secalert@redhat.com
  - url: 'https://security-tracker.debian.org/tracker/CVE-2021-3998'
    label: secalert@redhat.com
  - url: 'https://security.netapp.com/advisory/ntap-20221020-0003/'
    label: secalert@redhat.com
  - url: 'https://sourceware.org/bugzilla/show_bug.cgi?id=28770'
    label: secalert@redhat.com
  - url: >-
      https://sourceware.org/git/gitweb.cgi?p=glibc.git%3Bh=84d2d0fe20bdf94feed82b21b4d7d136db471f03
    label: secalert@redhat.com
  - url: >-
      https://sourceware.org/git/gitweb.cgi?p=glibc.git%3Bh=ee8d5e33adb284601c00c94687bc907e10aec9bb
    label: secalert@redhat.com
  - url: 'https://www.openwall.com/lists/oss-security/2022/01/24/4'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2021-3998'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2024633'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security-tracker.debian.org/tracker/CVE-2021-3998'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20221020-0003/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://sourceware.org/bugzilla/show_bug.cgi?id=28770'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://sourceware.org/git/gitweb.cgi?p=glibc.git%3Bh=84d2d0fe20bdf94feed82b21b4d7d136db471f03
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://sourceware.org/git/gitweb.cgi?p=glibc.git%3Bh=ee8d5e33adb284601c00c94687bc907e10aec9bb
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.openwall.com/lists/oss-security/2022/01/24/4'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-831302.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.01758
epssPercentile: 0.77389
ingestedAt: '2026-10-14T10:25:41.194Z'
---

## Overview

A flaw was found in glibc. The realpath() function can mistakenly return an unexpected value, potentially leading to information leakage and disclosure of sensitive data.

## Affected

- `glibc >= 2.33, < 2.35`
- `ontap_select_deploy_administration_utility`
- `h300s_firmware`
- `h500s_firmware`
- `h700s_firmware`
- `h410s_firmware`
- `h410c_firmware`

## Remediation

Upgrade past the affected range:

- `glibc 2.35`