CVE-2021-44228
Apache Log4j2 Remote Code Execution Vulnerability
Apache Log4j2
Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.15.0, this behavior has been disabled by default. From version 2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely removed. Note that this vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects.
Ransomware groups exploiting CVE-2021-44228
DragonForce is a major ransomware-as-a-service operation first observed in August 2023 that launched a formal affiliate program offering 80% revenue share, then rebranded as a "ransomware cartel" in 2025, gaining notoriety for high-profile attacks on UK retail
Exploitation is attributed to these groups across their recorded activity. It does not follow that every organisation they listed was reached through CVE-2021-44228 — the source data does not record an entry point per incident.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 10 December 2021. US federal agencies were required to remediate it by 24 December 2021. 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 100%, 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:H/I:H/A:H
Recent listings by these groups
Disclosures from the groups above, newest first.
Frequently asked questions
Is CVE-2021-44228 being exploited by ransomware groups?
Yes. CVE-2021-44228 is recorded as exploited by Dragonforce. Between them these groups account for 629 victim disclosures in this database. CISA also records this vulnerability as used in ransomware campaigns.
What does CVE-2021-44228 affect?
CVE-2021-44228 affects Apache Log4j2. Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.15.0, this behavior has been disabled by default. From version 2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely removed. Note that this vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects.
How severe is CVE-2021-44228?
CVE-2021-44228 is rated CRITICAL with a CVSS base score of 10. EPSS puts the probability of exploitation in the next 30 days at 100%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 24 December 2021.
How should organisations respond to CVE-2021-44228?
Apply the vendor patch for Apache Log4j2 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.