CVE-2021-37533 - CVE House
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Status published Unknown CVE-2021-37533

Apache Commons Net's FTP client trusts the host from PASV response by default

Vulnerability Description

Prior to Apache Commons Net 3.9.0, Net's FTP client trusts the host from PASV response by default. A malicious server can redirect the Commons Net code to use a different host, but the user has to connect to the malicious server in the first place. This may lead to leakage of information about services running on the private network of the client. The default in version 3.9.0 is now false to ignore such hosts, as cURL does. See https://issues.apache.org/jira/browse/NET-711.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Apache Commons would like to thank ZeddYu Lu for reporting this issue.

Affected Vendor

Apache Software Foundation

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Affected Software

Apache Commons Net
Vulnerable Versions:
Apache Commons Net

Timeline

Official Publish: December 3rd, 2022
Last Modified: April 24th, 2025
Added to House: July 21st, 2026

CVSS Vectors

No vector data available

Weaknesses (CWE)