CVE-2021-43396

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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS

3.3% chance of exploitation in the next 30 days; higher than 88% of CVEs (scores of 2026-10-25)

Published

2021-11-04

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• gnu:glibc
• oracle:communications_cloud_native_core_binding_support_function
• oracle:communications_cloud_native_core_network_function_cloud_native_environment
• oracle:communications_cloud_native_core_network_repository_function
• oracle:communications_cloud_native_core_security_edge_protection_proxy
• oracle:communications_cloud_native_core_unified_data_repository
• oracle:enterprise_operations_monitor

References

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

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