Is CVE-2021-0249 actively exploited?

No active exploitation of CVE-2021-0249 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-0249 be exploited remotely?

Yes. CVE-2021-0249 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-0249?

CVE-2021-0249 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2021-0249

CWE-120Published: April 22, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

On SRX Series devices configured with UTM services a buffer overflow vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS may allow an attacker to arbitrarily execute code or commands on the target to take over or otherwise impact the device by sending crafted packets to or through the device. This issue affects: Juniper Networks Junos OS on SRX Series: 15.1X49 versions prior to 15.1X49-D190; 17.4 versions prior to 17.4R2-S9; 17.4R3 and later versions prior to 18.1R3-S9; 18.2 versions prior to 18.2R3-S1; 18.3 versions prior to 18.3R2-S3, 18.3R3; 18.4 versions prior to 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S4, 19.1R2; 19.2 versions prior to 19.2R1-S1, 19.2R2. An indicator of compromise can be the following text in the UTM log: RT_UTM: AV_FILE_NOT_SCANNED_PASSED_MT:

NVD Source

Technical Analysis

CVE-2021-0249 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.