Apache Log4j2 JNDI features do not protect against attacker controlled LDAP and other JNDI related endpoints
CVE-2021-44228

10CRITICAL

Key Information:

Vendor
Apache
Status
Apache Log4j2
Vendor
CVE Published:
10 December 2021

Badges

📈 Score: 296💰 Ransomware👾 Exploit Exists🟡 Public PoC🟣 EPSS 94%🦅 CISA Reported

What is CVE-2021-44228?

CVE-2021-44228 is a critical vulnerability affecting Apache Log4j2, a popular logging utility widely used in various Java applications for logging messages and managing application logs. This vulnerability arises from insecure handling of Java Naming and Directory Interface (JNDI) features, which can allow attackers to execute arbitrary code remotely. Organizations utilizing affected versions of Log4j2 may find themselves at risk, as potential exploitation could lead to serious security breaches, unauthorized access to sensitive data, and overall compromise of the application environment.

Technical Details

The vulnerability specifically lies in the JNDI features of Apache Log4j2 versions 2.0-beta9 through 2.15.0, excluding certain security releases. It allows an attacker who can manipulate log messages to execute arbitrary code by employing attacker-controlled LDAP or other JNDI endpoints. This misuse occurs when message lookup substitution is enabled, which can be inadvertently configured in applications. Starting from Log4j version 2.15.0, this feature was disabled by default, and it was entirely removed from version 2.16.0 onward.

Potential Impact of CVE-2021-44228

  1. Remote Code Execution: Attackers can exploit this vulnerability to execute arbitrary code on the server, leading to the complete compromise of the system. This means they can run commands, access files, or install malicious software.

  2. Data Breaches: The exploitation allows attackers to extract sensitive information from compromised systems, potentially leading to data theft and leakage of confidential data.

  3. Widespread Vulnerability: Due to the widespread use of Apache Log4j2 in various applications and services, the exploitation of this vulnerability could lead to large-scale incidents affecting numerous organizations, making it a high-priority risk for cybersecurity.

CISA Reported

CISA provides regional cyber and physical services to support security and resilience across the United States. CISA monitor the most dangerious vulnerabilities and have identifed as being exploited and is known by the CISA as enabling ransomware campaigns.

The CISA's recommendation is: For all affected software assets for which updates exist, the only acceptable remediation actions are: 1) Apply updates; OR 2) remove affected assets from agency networks. Temporary mitigations using one of the measures provided at https://www.cisa.gov/uscert/ed-22-02-apache-log4j-recommended-mitigation-measures are only acceptable until updates are available.

Affected Version(s)

Apache Log4j2 2.0-beta9

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

log4j-scan
Created by fullhunt

log4j-shell-poc
Created by kozmer

log4shell-vulnerable-app
Created by christophetd

References

https://logging.apache.org/log4j/2.x/security.html
http://www.openwall.com/lists/oss-security/2021/12/10/1
mailing-list
http://www.openwall.com/lists/oss-security/2021/12/10/2
mailing-list

EPSS Score

94% chance of being exploited in the next 30 days.

CVSS V3.1

Score:
10
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • 🟡

    Public PoC available

  • 💰

    Used in Ransomware

  • 👾

    Exploit known to exist

  • 🦅

    CISA Reported

  • Vulnerability published

  • Vulnerability Reserved

Credit

This issue was discovered by Chen Zhaojun of Alibaba Cloud Security Team.
.