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NVD / CVE Program· CNA VulDB

CVE-2021-4327: SerenityOS TypedArray.cpp initialize_typed_array_from_array_buffer integer overflow

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.93% (FIRST EPSS); higher than 60.9% 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.
  • No fixed version is recorded, but the references include a patch (commit or PR) link.
  • Severity is disputed: the assigning authority (CNA) scores it 5.5, NVD 9.8.

Low priority for now. See the fix and affected versions sections below.

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

A vulnerability was found in SerenityOS. It has been rated as critical. Affected by this issue is the function initialize_typed_array_from_array_buffer in the library Userland/Libraries/LibJS/Runtime/TypedArray.cpp. The manipulation leads to integer overflow. The exploit has been disclosed to the public and may be used. Continious delivery with rolling releases is used by this product. Therefore, no version details of affected nor updated releases are available. The patch is identified as f6c6047e49f1517778f5565681fb64750b14bf60. It is recommended to apply a patch to fix this issue. VDB-222074 is the identifier assigned to this vulnerability.

CriticalCVSS 9.8 · v3.1—No exploit No fix recorded
Published
Mar 1, 2023
Updated
Jun 17, 2026
EPSS
0.9% · 60th percentile

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.9%

CNA vs NVD score

NVD
9.8
CNA · VulDB
5.5
4.3 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

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

Follow CVE-2021-4327

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

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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.

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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
serenityosserenityos

Affected versions

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

  • serenityos serenityosbefore 2021-01-27

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulDB). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a SerenityOS

    • n/aaffected

Same product

serenityos: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-31272SerenityOS before commit 3844e8569689dd476064a0759d704bc64fb3ca2c contains a directory traversal vulnerability in tar/unzip that may lead to
    40Plan
  • CVE-2021-30045SerenityOS 2021-03-27 contains a buffer overflow vulnerability in the EndOfCentralDirectory::read() function.
    37Monitor
  • CVE-2021-28874SerenityOS fixed as of c9f25bca048443e317f1994ba9b106f2386688c3 contains a buffer overflow vulnerability in LibTextCode through opening a cr
    31Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2021-27343Apr 6, 2021 · SerenityOS Unspecified is affected by: Buffer Overflow.
    31Monitor
  • ← EarlierCVE-2021-33185Jun 18, 2021 · SerenityOS contains a buffer overflow in the set_range test in TestBitmap which could allow attackers to obtain sensitive information.
    30Monitor
  • ← EarlierCVE-2021-33186Jun 18, 2021 · SerenityOS in test-crypto.cpp contains a stack buffer overflow which could allow attackers to obtain sensitive information.
    30Monitor

Remediation

Which version to upgrade to

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

No fix version is recorded for this entry. Check the references for vendor advisories.

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.

Credits

All researchers

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

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

Weakness class (CWE)

CWE-190 · Integer Overflow or Wraparound

CVSS vector

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

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.

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (2 more)

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

All records