6.5

CVE-2021-37533: apache software foundation apache commons net Improper Input Validation

CVSS: 6.5v3.1MediumModified
AliasesUBUNTU-CVE-2021-37533USN-6037-1DEBIAN-CVE-2021-37533
Published 03-12-2022Last modified 24-04-2025
Open JSON

Vulnerability summary

CVE-2021-37533 is a medium (CVSS 6.5) Improper Input Validation vulnerability in apache software foundation apache commons net. EPSS estimates a 2.13% chance of exploitation in the next 30 days, higher than 81.6% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
2.13%
0%100%
Low · +0.08 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-2FW7-3RRC-XGM6

Timeline

  1. 03-12-2022
    PublishedVulnerability first disclosed.
  2. 24-04-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

7 scores · 7 sources · 1 version

EPSS trend

Probability

2.13%

Chance of exploitation in the next 30 days

Percentile

82%

Versus all other CVEs

30-day change

+0.08 pp

From 2.05% on 19-09-2026

19-09-202619-10-2026
EPSS score
2.13%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard3 products
  • druid< 35.0.1-r1 | < 37.0.0-r56 | < 37.0.0-r14
  • rangerAll versions (No fix recorded)
  • spark-3.5-scala-2.13< 3.5.7-r2
Debian2 products
  • libcommons-net-java< 3.9.0-1 | < 3.6-1+deb11u1 | < 3.6-1+deb10u1
  • debian_linuxEOL10.0 | 11.0
Apache1 product
Apache software foundation1 product
Commons-net1 product
  • commons-net< 3.9.0
Opensuse1 product
  • apache-commons-net&distro=openSUSE Tumbleweed< 3.9.0-1.1
Ubuntu1 product
  • libcommons-net-java< 3.4-2ubuntu2+esm1 | < 3.6-1+deb11u1build0.18.04.1 | < 3.6-1+deb11u1build0.20.04.1 | < 3.6-1+deb11u1build0.22.04.1
Wolfi1 product
  • druid< 35.0.1-r1 | < 37.0.0-r56 | < 37.0.0-r14

8 vendors · 11 products

References

14 links
Show all 14 references