Is CVE-2021-33304 actively exploited?

No active exploitation of CVE-2021-33304 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-33304 be exploited remotely?

Yes. CVE-2021-33304 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-33304?

CVE-2021-33304 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2021-33304

CWE-415Published: February 15, 2023· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

Double Free vulnerability in virtualsquare picoTCP v1.7.0 and picoTCP-NG v2.1 in modules/pico_fragments.c in function pico_fragments_reassemble, allows attackers to execute arbitrary code.

NVD Source

Technical Analysis

CVE-2021-33304 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.