Is CVE-2021-44548 actively exploited?

No active exploitation of CVE-2021-44548 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-44548 be exploited remotely?

Yes. CVE-2021-44548 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-44548?

CVE-2021-44548 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2021-44548

CWE-20Published: December 23, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

An Improper Input Validation vulnerability in DataImportHandler of Apache Solr allows an attacker to provide a Windows UNC path resulting in an SMB network call being made from the Solr host to another host on the network. If the attacker has wider access to the network, this may lead to SMB attacks, which may result in: * The exfiltration of sensitive data such as OS user hashes (NTLM/LM hashes), * In case of misconfigured systems, SMB Relay Attacks which can lead to user impersonation on SMB Shares or, in a worse-case scenario, Remote Code Execution This issue affects all Apache Solr versions prior to 8.11.1. This issue only affects Windows.

NVD Source

Technical Analysis

CVE-2021-44548 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.