Cloudanix VulnDB

CVE-2021-3326

High · 7.5

CVSS

7.5

EPSS

3.8%

Published

Jan 27, 2021

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A bug in a core system library can make programs crash when they receive certain badly formed text, which attackers can trigger over the network to interrupt services.

Exploitation
Remote Unauthenticated
Attacker needs
None
Complexity
Low
Impact
Denial Of Service
Component
Library
Class
Denial of service
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

iconv in glibc 2.32 and earlier aborts the calling process with an assertion failure when fed invalid byte sequences in the ISO-2022-JP-3 encoding, resulting in denial of service.

Why it matters to the business

Applications that process untrusted text through iconv (including web rendering components on Debian and Ubuntu) can be crashed remotely, interrupting service availability and requiring restarts until patches are applied.

How an attack unfolds

An attacker supplies a crafted invalid ISO-2022-JP-3 byte sequence to any code path that invokes iconv on untrusted data; the library hits an assertion and terminates the process, achieving denial of service without further interaction.

How to fix it

Upgrade affected webkit2gtk packages to the listed fixed versions: Debian 10/11/12/13 to 2.22.0-2 and Ubuntu 18.04 LTS to 2.22.2-0ubuntu0.18.04.1 or newer; rebuild or redeploy any statically linked dependents.

How to confirm the fix worked

Confirm the installed package version matches or exceeds the fixed version for each distribution; run regression tests that feed ISO-2022-JP-3 test vectors through iconv and verify no assertion aborts occur.

Typical attack path

  1. Identify a target process or service that uses iconv on attacker-controlled input
  2. Craft an invalid ISO-2022-JP-3 sequence that triggers the assertion
  3. Deliver the sequence over the network or via a file upload
  4. Observe process termination and service outage

How to detect it

Review system and application logs for abrupt terminations accompanied by glibc assertion messages referencing iconv or ISO-2022-JP-3; correlate with inbound requests containing non-UTF-8 or unusual encoding headers.

What your security team should do

  • Apply the distribution-specific webkit2gtk updates immediately on all affected systems
  • Scan for and rebuild any custom applications that statically link older glibc iconv code
  • Add monitoring for unexpected process crashes in services that handle internationalized text

The record

The iconv function in the GNU C Library (aka glibc or libc6) 2.32 and earlier, when processing invalid input sequences in the ISO-2022-JP-3 encoding, fails an assertion in the code path and aborts the program, potentially resulting in a denial of service.

Affected packages

Ecosystem Package Introduced Fixed
AlmaLinux:8 glibc-benchtests 0 2.28-151.el8
AlmaLinux:8 glibc-nss-devel 0 2.28-151.el8
AlmaLinux:8 glibc-static 0 2.28-151.el8
AlmaLinux:8 nss_hesiod 0 2.28-151.el8
Debian:10 glibc 0 2.28-10+deb10u2
Debian:11 glibc 0 2.31-10
Debian:12 glibc 0 2.31-10
Debian:13 glibc 0 2.31-10
Mageia:7 glibc 0 2.29-22.mga7
Red Hat:enterprise_linux:8::appstream compat-libpthread-nonshared 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-all-langpacks 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-benchtests 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-common 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-debuginfo 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-debuginfo-common 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-devel 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-headers 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-aa 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-af 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-agr 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ak 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-am 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-an 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-anp 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ar 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-as 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ast 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ayc 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-az 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-be 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-bem 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ber 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-bg 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-bhb 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-bho 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-bi 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-bn 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-bo 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-br 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-brx 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-bs 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-byn 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ca 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ce 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-chr 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-cmn 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-crh 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-cs 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-csb 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-cv 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-cy 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-da 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-de 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-doi 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-dsb 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-dv 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-dz 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-el 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-en 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-eo 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-es 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-et 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-eu 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-fa 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ff 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-fi 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-fil 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-fo 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-fr 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-fur 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-fy 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ga 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-gd 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-gez 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-gl 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-gu 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-gv 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ha 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-hak 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-he 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-hi 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-hif 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-hne 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-hr 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-hsb 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ht 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-hu 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-hy 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ia 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-id 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ig 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ik 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-is 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-it 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-iu 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ja 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ka 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-kab 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-kk 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-kl 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-km 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-kn 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ko 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-kok 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ks 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ku 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-kw 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ky 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-lb 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-lg 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-li 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-lij 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ln 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-lo 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-lt 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-lv 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-lzh 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mag 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mai 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mfe 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mg 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mhr 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mi 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-miq 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mjw 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mk 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ml 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mn 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mni 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mr 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ms 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-mt 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-my 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-nan 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-nb 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-nds 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ne 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-nhn 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-niu 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-nl 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-nn 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-nr 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-nso 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-oc 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-om 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-or 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-os 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-pa 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-pap 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-pl 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ps 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-pt 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-quz 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-raj 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ro 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ru 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-rw 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sa 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sah 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sat 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sc 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sd 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-se 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sgs 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-shn 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-shs 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-si 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sid 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sk 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sl 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sm 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-so 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sq 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sr 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ss 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-st 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sv 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-sw 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-szl 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ta 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-tcy 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-te 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-tg 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-th 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-the 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ti 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-tig 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-tk 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-tl 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-tn 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-to 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-tpi 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-tr 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ts 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-tt 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ug 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-uk 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-unm 0 0:2.28-151.el8
Red Hat:enterprise_linux:8::appstream glibc-langpack-ur 0 0:2.28-151.el8

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