CVE-2021-41766Network attack vector

Classpath-dependent compromise via unfiltered JMX credential objects

Published Jan 26, 2022 · Updated Aug 4, 2024

Unsafe deserialization in Apache Karaf before 4.3.6 allows remote attackers to trigger classpath-dependent impacts through JMX. The RMI connector accepts serialized credential objects without limiting their classes to java.lang.String before authentication. No credentials or user interaction are required, but consequences depend on gadget-capable system classes, which are limited in the default JMX server classpath.

CVSS severity8.1
High
EPSS probability2.03%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe deserialization in Apache Karaf before 4.3.6 allows remote attackers to trigger classpath-dependent impacts through JMX. The RMI connector accepts serialized credential objects without limiting their classes to java.lang.String before authentication. No credentials or user interaction are required, but consequences depend on gadget-capable system classes, which are limited in the default JMX server classpath.

The record

CVE
CVE-2021-41766
Published
Jan 26, 2022
Updated
Aug 4, 2024
Vendor
The Apache Software Foundation
Product
Apache Karaf
Classifications
CWE-502, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 26, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Apache Karaf <4.3.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Karafversion=Apache Karaf <4.3.6

Published CVSS scores

6.8NIST National Vulnerability DatabaseAV:N/AC:M/Au:N/C:P/I:P/A:P
8.1NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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