Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-43396

CVE-2021-43396HIGH

n/a n/a — 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 …

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  H  N    7.5   .0329   88.3     —

AFFECTED
  Product  Versions  Fixed
  n/a      n/a –     —

TIMELINE
  Nov 4   Reserved by mitre
  Nov 4   Published (CNA: mitre)
  Oct 14  ENRICHED — CVE-2021-43396. Received CVSS 7.5 and CPE data from NVD.
  Oct 14  EXPLOIT PUBLISHED — CVE-2021-43396. Public exploit reference added.

CNA: mitre · CVSS v3.1 · 5 references · NVD status: Modified

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.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
November 4, 2021	Reserved	Reserved by mitre
November 4, 2021	Published	Published (CNA: mitre)
October 14, 2026	ENRICHED	ENRICHED — CVE-2021-43396. Received CVSS 7.5 and CPE data from NVD.
October 14, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2021-43396. Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
n/a	n/a	—	n/a	—

References (5)

https://blog.tuxcare.com/vulnerability/vulnerability-in-iconv-identified-by-tuxcare-team-cve-2021-43396 [Exploit, Third Party Advisory]
https://cert-portal.siemens.com/productcert/html/ssa-398330.html
https://sourceware.org/bugzilla/show_bug.cgi?id=28524 [Exploit, Issue Tracking, Third Party Advisory]
https://sourceware.org/git/?p=glibc.git%3Ba=commit%3Bh=ff012870b2c02a62598c04daa1e54632e020fd7d
https://www.oracle.com/security-alerts/cpujul2022.html [Patch, Third Party Advisory]

Authoritative record: CVE-2021-43396 at cve.org

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