CRITICAL · CVSS 10 CISA Known Exploited Vulnerability Used in ransomware attacks

CVE-2023-46604

Apache ActiveMQ Deserialization of Untrusted Data Vulnerability

Apache ActiveMQ

The Java OpenWire protocol marshaller is vulnerable to Remote Code Execution. This vulnerability may allow a remote attacker with network access to either a Java-based OpenWire broker or client to run arbitrary shell commands by manipulating serialized class types in the OpenWire protocol to cause either the client or the broker (respectively) to instantiate any class on the classpath. Users are recommended to upgrade both brokers and clients to version 5.15.16, 5.16.7, 5.17.6, or 5.18.3 which fixes this issue.

CVSS
10
CRITICAL
EPSS
99.7%
30-day exploitation
Ransomware groups
1
recorded exploiting
Published
27 Oct 2023
CWE-502

Ransomware groups exploiting CVE-2023-46604

Ransomhub 842 victims tracked

The group emerged in mid-February 2024 and has already listed several organizations as alleged victims of their attacks, resulting from extortion through encryption and data leaks. The announcement of the sale of the new Ransomware-as-a-Service (RaaS) by Ranso

Exploitation is attributed to these groups across their recorded activity. It does not follow that every organisation they listed was reached through CVE-2023-46604 — the source data does not record an entry point per incident.

Exploitation status

CISA Known Exploited Vulnerabilities

Listed by CISA on 2 November 2023. US federal agencies were required to remediate it by 23 November 2023. CISA records this vulnerability as known to be used in ransomware campaigns.

EPSS — exploitation probability

FIRST puts the probability of exploitation activity in the next 30 days at 99.7%, which is higher than 99.9% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H

Recent listings by these groups

Disclosures from the groups above, newest first.

Frequently asked questions

Is CVE-2023-46604 being exploited by ransomware groups?

Yes. CVE-2023-46604 is recorded as exploited by Ransomhub. Between them these groups account for 842 victim disclosures in this database. CISA also records this vulnerability as used in ransomware campaigns.

What does CVE-2023-46604 affect?

CVE-2023-46604 affects Apache ActiveMQ. The Java OpenWire protocol marshaller is vulnerable to Remote Code Execution. This vulnerability may allow a remote attacker with network access to either a Java-based OpenWire broker or client to run arbitrary shell commands by manipulating serialized class types in the OpenWire protocol to cause either the client or the broker (respectively) to instantiate any class on the classpath. Users are recommended to upgrade both brokers and clients to version 5.15.16, 5.16.7, 5.17.6, or 5.18.3 which fixes this issue.

How severe is CVE-2023-46604?

CVE-2023-46604 is rated CRITICAL with a CVSS base score of 10. EPSS puts the probability of exploitation in the next 30 days at 99.7%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 23 November 2023.

How should organisations respond to CVE-2023-46604?

Apply the vendor patch for Apache ActiveMQ as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.