{"id":"CVE-2021-43396","aliases":["AZL-6443","CLSA-2021-1636389414","CLSA-2021-1636389447","CLSA-2021-1637583639","DEBIAN-CVE-2021-43396","EUVD-2021-30331","GHSA-73g2-m4v3-6c2h","OESA-2021-1438"],"status":"disputed","title":"In iconvdata/iso-2022-jp-3.c in the GNU C Library (aka glibc) 2.34, remote attackers can force...","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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.03293,"percentile":0.88655,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"published":"2021-11-04T19:52:49Z","modified":"2026-10-24T10:31:00Z","fixes":[{"ecosystem":"Azure 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{"fixed":"2.12-2.215.el6.cloudlinux.els"}]}],"bundled":2},{"source":"osv","ecosystem":"TuxCare:CentOS:6","package":"glibc-utils","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.12-2.215.el6.cloudlinux.els"}]}],"bundled":2},{"source":"osv","ecosystem":"TuxCare:CentOS:6","package":"nscd","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.12-2.215.el6.cloudlinux.els"}]}],"bundled":2},{"source":"osv","ecosystem":"Debian:12","package":"glibc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.32-5"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"glibc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.32-5"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"glibc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.32-5"}]}]},{"source":"osv","ecosystem":"openEuler:20.03-LTS-SP1","package":"glibc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.28-79.oe1"}]}]},{"source":"osv","ecosystem":"openEuler:20.03-LTS-SP2","package":"glibc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.28-79.oe1"}]}]}],"products":[{"vendor":"gnu","product":"glibc"},{"vendor":"oracle","product":"communications_cloud_native_core_binding_support_function"},{"vendor":"oracle","product":"communications_cloud_native_core_network_function_cloud_native_environment"},{"vendor":"oracle","product":"communications_cloud_native_core_network_repository_function"},{"vendor":"oracle","product":"communications_cloud_native_core_security_edge_protection_proxy"},{"vendor":"oracle","product":"communications_cloud_native_core_unified_data_repository"},{"vendor":"oracle","product":"enterprise_operations_monitor"},{"vendor":"siemens","product":"simatic s7-1500 cpu 1518-4 pn/dp mfp"},{"vendor":"siemens","product":"simatic s7-1500 cpu 1518f-4 pn/dp mfp"},{"vendor":"siemens","product":"siplus s7-1500 cpu 1518-4 pn/dp mfp"}],"references":[{"url":"https://sourceware.org/bugzilla/show_bug.cgi?id=28524","tags":["x_refsource_MISC","x_transferred","Exploit","Issue Tracking","Third Party Advisory","report"]},{"url":"https://sourceware.org/git/?p=glibc.git%3Ba=commit%3Bh=ff012870b2c02a62598c04daa1e54632e020fd7d","tags":["x_refsource_MISC","x_transferred","web"]},{"url":"https://blog.tuxcare.com/vulnerability/vulnerability-in-iconv-identified-by-tuxcare-team-cve-2021-43396","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","evidence"]},{"url":"https://www.oracle.com/security-alerts/cpujul2022.html","tags":["x_transferred","Patch","Third Party Advisory","fix"]},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-43396","tags":["web","advisory"]},{"url":"https://sourceware.org/git/?p=glibc.git;a=commit;h=ff012870b2c02a62598c04daa1e54632e020fd7d"},{"url":"https://github.com/advisories/GHSA-73g2-m4v3-6c2h"},{"url":"https://errata.cloudlinux.com/ubuntu16_04/CLSA-2021-1636389414","tags":["advisory"]},{"url":"https://errata.cloudlinux.com/ol6/CLSA-2021-1636389447.html","tags":["advisory"]},{"url":"https://errata.cloudlinux.com/els6/CLSA-2021-1637583639.html","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-43396","tags":["advisory"]},{"url":"https://www.openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2021-1438","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2021-43396","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.","status":"disputed","published":"2021-11-04T19:52:49Z","modified":"2026-10-14T11:53:51.689Z","updated_at":"2026-11-02T14:32:56.689433Z"}],"euvd":[{"id":"EUVD-2021-30331","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.","status":"published","published":"2021-11-04T19:52:49Z","modified":"2026-10-14T11:53:51Z","updated_at":"2026-11-02T17:27:15.969628Z"}],"ghsa":[{"id":"GHSA-73g2-m4v3-6c2h","title":"In iconvdata/iso-2022-jp-3.c in the GNU C Library (aka glibc) 2.34, remote attackers can force...","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.","status":"published","published":"2022-05-24T19:19:43Z","modified":"2026-10-14T12:31:23Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:13:24.188405Z"}],"nvd":[{"id":"CVE-2021-43396","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.","status":"disputed","published":"2021-11-04T20:15:09.223Z","modified":"2026-10-14T12:17:16.16Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:07:00.549994Z"}],"osv":[{"id":"AZL-6443","title":"CVE-2021-43396 affecting package glibc for versions less than 2.35-1","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.","status":"published","published":"2021-11-04T20:15:09Z","modified":"2026-04-21T04:32:24.148535Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:28:08.076947Z"},{"id":"CVE-2021-43396","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.","status":"published","published":"2021-11-04T20:15:09.223Z","modified":"2026-10-24T10:31:00.825304227Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:44:21.877444Z"},{"id":"DEBIAN-CVE-2021-43396","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.","status":"published","published":"2021-11-04T20:15:09.223Z","modified":"2026-10-15T09:47:39.638761648Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:45:35.799676Z"},{"id":"OESA-2021-1438","title":"glibc security update","description":"The GNU C Library project provides the core libraries for the GNU system and GNU/Linux systems, as well as many other systems that use Linux as the kernel. These libraries provide critical APIs including ISO C11, POSIX.1-2008, BSD, OS-specific APIs and more. These APIs include such foundational facilities as open, read, write, malloc, printf, getaddrinfo, dlopen, pthread_create, crypt,  login, exit and more.\r\n\r\nSecurity Fix(es):\r\n\r\nIn iconvdata/iso-2022-jp-3.c in the GNU C Library (aka glibc) 2.34, remote attackers can force iconv() to emit a spurious \u0026apos;\\0\u0026apos; 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.(CVE-2021-43396)","status":"published","published":"2021-11-19T11:04:42Z","modified":"2026-08-18T01:16:12.536753094Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:52:38.987987Z"},{"id":"CLSA-2021-1636389414","title":"Fix CVE(s): CVE-2021-3326, CVE-2021-43396","description":"\n   * SECURITY UPDATE: assertion failure in ISO-2022-JP-3 module\n     - debian/patches/any/CVE-2021-3326.patch: enqueue a second wide\n       character which cannot be written immediately\n       in the state variable.\n     - CVE-2021-3326\n   * SECURITY UPDATE: emission of a spurious '\\0' character on state reset\n     - debian/patches/any/CVE-2021-3326.patch: check actual\n       stored character in state reset code.\n     - CVE-2021-43396","status":"published","published":"2021-11-08T16:36:54Z","modified":"2026-06-04T10:03:50.578836Z","updated_at":"2026-11-02T15:43:39.801198Z"},{"id":"CLSA-2021-1636389447","title":"Fixed CVEs in glibc: CVE-2021-43396, CVE-2021-3326","description":"- CVE-2021-3326: avoid denial of service due to a failed assertion\n- CVE-2021-43396: check actual stored character in state reset code","status":"published","published":"2021-11-08T16:37:27Z","modified":"2026-10-21T10:48:01.242742203Z","updated_at":"2026-11-02T15:43:39.801198Z"},{"id":"CLSA-2021-1637583639","title":"Fix of CVE: CVE-2021-3326, CVE-2021-43396","description":"- CVE-2021-3326: avoid denial of service due to a failed assertion\n- CVE-2021-43396: check actual stored character in state reset code","status":"published","published":"2021-11-22T12:20:39Z","modified":"2026-06-01T00:32:14.168525257Z","updated_at":"2026-11-02T15:43:39.801198Z"}]}}