Skip to content
Noroxi
NVD / CVE Program· CNA mitre

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

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 3.2% (FIRST EPSS); higher than 88.4% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: glibc (Debian:12) 2.32-5.

Low priority for now. Upgrade to glibc (Debian:12) 2.32-5 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Nov 4, 2021
Updated
Oct 14, 2026
EPSS
3.2% · 88th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 3.2%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-43396

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for gnu records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
gnuglibc
oraclecommunications cloud native core binding support function
oraclecommunications cloud native core network function cloud native environment
oraclecommunications cloud native core network repository function
oraclecommunications cloud native core security edge protection proxy
oraclecommunications cloud native core unified data repository
oracleenterprise operations monitor

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • gnu glibc2.34
  • oracle communications cloud native core binding support function22.1.3
  • oracle communications cloud native core network function cloud native environment22.1.0
  • oracle communications cloud native core network repository function22.1.2
  • oracle communications cloud native core network repository function22.2.0
  • oracle communications cloud native core security edge protection proxy22.1.1
  • oracle communications cloud native core unified data repository22.2.0
  • oracle enterprise operations monitor4.3
  • oracle enterprise operations monitor4.4
  • oracle enterprise operations monitor5.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12glibcbefore 2.32-52.32-5

Same product

gnu: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-4911Glibc: buffer overflow in ld.so leading to privilege escalationKEV
    80Now
  • CVE-2015-0235Heap-based buffer overflow in the __nss_hostname_digits_dots function in glibc 2.2, and other 2.x versions before 2.18, allows context-depen
    68This week
  • CVE-2015-7547Multiple stack-based buffer overflows in the (1) send_dg and (2) send_vc functions in the libresolv library in the GNU C Library (aka glibc
    60This week

Published before and after this one in the same product

  • ← EarlierCVE-2021-35942Jul 22, 2021 · The wordexp function in the GNU C Library (aka glibc) through 2.33 may crash or read arbitrary memory in parse_param (in posix/wordexp.c) wh
    37Monitor
  • ← EarlierCVE-2021-38604Aug 12, 2021 · In librt in the GNU C Library (aka glibc) through 2.34, sysdeps/unix/sysv/linux/mq_notify.c mishandles certain NOTIFY_REMOVED data, leading
    31Monitor
  • Later →CVE-2022-23218Jan 14, 2022 · The deprecated compatibility function svcunix_create in the sunrpc module of the GNU C Library (aka glibc) through 2.34 copies its path argu
    41Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:glibc2.32-5 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
high · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
High
Availability impact
None

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records