---
id: CVE-2021-43396
title: >-
  In iconvdata/iso-2022-jp-3.c in the GNU C Library (aka glibc) 2.34, remote
  attackers can force iconv() to emit a spurious '\0' character via crafted
  ISO-2022-JP-3 data that is accompanied by an internal state reset
summary: >-
  In iconvdata/iso-2022-jp-3.c in the GNU C Library (aka glibc) 2.34, remote
  attackers can force iconv() to emit a spurious '\0' character via crafted
  ISO-2022-JP-3 data that is accompanied by an internal state reset. This may
  affect data …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'
vendor: gnu
product: glibc
affected:
  - glibc = 2.34
  - communications_cloud_native_core_binding_support_function = 22.1.3
  - >-
    communications_cloud_native_core_network_function_cloud_native_environment =
    22.1.0
  - communications_cloud_native_core_network_repository_function = 22.1.2
  - communications_cloud_native_core_network_repository_function = 22.2.0
  - communications_cloud_native_core_security_edge_protection_proxy = 22.1.1
  - communications_cloud_native_core_unified_data_repository = 22.2.0
  - enterprise_operations_monitor = 4.3
  - enterprise_operations_monitor = 4.4
  - enterprise_operations_monitor = 5.0
published: '2021-11-04'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T12:17:16.160'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-43396'
references:
  - url: >-
      https://blog.tuxcare.com/vulnerability/vulnerability-in-iconv-identified-by-tuxcare-team-cve-2021-43396
    label: cve@mitre.org
  - url: 'https://sourceware.org/bugzilla/show_bug.cgi?id=28524'
    label: cve@mitre.org
  - url: >-
      https://sourceware.org/git/?p=glibc.git%3Ba=commit%3Bh=ff012870b2c02a62598c04daa1e54632e020fd7d
    label: cve@mitre.org
  - url: 'https://www.oracle.com/security-alerts/cpujul2022.html'
    label: cve@mitre.org
  - url: >-
      https://blog.tuxcare.com/vulnerability/vulnerability-in-iconv-identified-by-tuxcare-team-cve-2021-43396
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://sourceware.org/bugzilla/show_bug.cgi?id=28524'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://sourceware.org/git/?p=glibc.git%3Ba=commit%3Bh=ff012870b2c02a62598c04daa1e54632e020fd7d
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpujul2022.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.03293
epssPercentile: 0.88215
ingestedAt: '2026-10-14T12:29:10.827Z'
---

## Overview

In iconvdata/iso-2022-jp-3.c in the GNU C Library (aka glibc) 2.34, remote attackers can force iconv() to emit a spurious '\0' character via crafted ISO-2022-JP-3 data that is accompanied by an internal state reset. This may affect data integrity in certain iconv() use cases. NOTE: the vendor states "the bug cannot be invoked through user input and requires iconv to be invoked with a NULL inbuf, which ought to require a separate application bug to do so unintentionally. Hence there's no security impact to the bug.

## Affected

- `glibc = 2.34`
- `communications_cloud_native_core_binding_support_function = 22.1.3`
- `communications_cloud_native_core_network_function_cloud_native_environment = 22.1.0`
- `communications_cloud_native_core_network_repository_function = 22.1.2`
- `communications_cloud_native_core_network_repository_function = 22.2.0`
- `communications_cloud_native_core_security_edge_protection_proxy = 22.1.1`
- `communications_cloud_native_core_unified_data_repository = 22.2.0`
- `enterprise_operations_monitor = 4.3`
- `enterprise_operations_monitor = 4.4`
- `enterprise_operations_monitor = 5.0`

## Remediation

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