CVE-2021-43396

Name: CVE-2021-43396
Creator: NVD / NIST
Published: 2021-11-04T20:15:09.223+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 2.94%

Last modified Jun 17, 2026

CVE-2021-43396 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 2.94% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

2.94%

85.4th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Gnu	Glibc	2.34
Oracle	Communications Cloud Native Core Binding Support Function	22.1.3
Oracle	Communications Cloud Native Core Network Function Cloud Native Environment	22.1.0
Oracle	Communications Cloud Native Core Network Repository Function	22.1.2
Oracle	Communications Cloud Native Core Network Repository Function	22.2.0
Oracle	Communications Cloud Native Core Security Edge Protection Proxy	22.1.1
Oracle	Communications Cloud Native Core Unified Data Repository	22.2.0
Oracle	Enterprise Operations Monitor	4.3
Oracle	Enterprise Operations Monitor	4.4
Oracle	Enterprise Operations Monitor	5.0

References

https://blog.tuxcare.com/vulnerability/vulnerability-in-iconv-identified-by-tuxcare-team-cve-2021-43396Exploit, Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=28524Exploit, Issue Tracking, Third Party Advisory
https://sourceware.org/git/?p=glibc.git%3Ba=commit%3Bh=ff012870b2c02a62598c04daa1e54632e020fd7d
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch, Third Party Advisory
https://blog.tuxcare.com/vulnerability/vulnerability-in-iconv-identified-by-tuxcare-team-cve-2021-43396Exploit, Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=28524Exploit, Issue Tracking, Third Party Advisory
https://sourceware.org/git/?p=glibc.git%3Ba=commit%3Bh=ff012870b2c02a62598c04daa1e54632e020fd7d
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch, Third Party Advisory

Timeline

Published: Nov 4, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-43396?

How severe is CVE-2021-43396?

CVE-2021-43396 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 2.94% probability of exploitation in the next 30 days.

How do I fix CVE-2021-43396?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-43396?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST