CVE-2021-44228

Description

A flaw was found in the Apache Log4j logging library in versions from 2.0.0 and before 2.15.0. A remote attacker who can control log messages or log message parameters, can execute arbitrary code on the server via JNDI LDAP endpoint.

Security Bulletin

https://access.redhat.com/security/vulnerabilities/RHSB-2021-009

Statement

This issue only affects log4j versions between 2.0 and 2.14.1. In order to exploit this flaw you need:

  • A remotely accessible endpoint with any protocol (HTTP, TCP, etc) that allows an attacker to send arbitrary data,
  • A log statement in the endpoint that logs the attacker controlled data.

In Red Hat OpenShift Logging the vulnerable log4j library is shipped in the Elasticsearch components. Because Elasticsearch is not susceptible to remote code execution with this vulnerability due to use of the Java Security Manager and because access to these components is limited, the impact by this vulnerability is reduced to Moderate.

As per upstream applications using Log4j 1.x may be impacted by this flaw if their configuration uses JNDI. However, the risk is much lower. This flaw in Log4j 1.x is tracked via https://access.redhat.com/security/cve/CVE-2021-4104 and has been rated as having Moderate security impact.

CodeReady Studio version 12.21.1 was released containing a fix for this vulnerability.

The following products are NOT affected by this flaw and have been explicitly listed here for the benefit of our customers.

  • Red Hat Enterprise Linux
  • Red Hat Advanced Cluster Management for Kubernetes
  • Red Hat Advanced Cluster Security for Kubernetes
  • Red Hat Ansible Automation Platform (Engine and Tower)
  • Red Hat Certificate System
  • Red Hat Directory Server
  • Red Hat Identity Management
  • Red Hat CloudForms
  • Red Hat Update Infrastructure
  • Red Hat Satellite
  • Red Hat Ceph Storage
  • Red Hat Gluster Storage
  • Red Hat OpenShift Data Foundation
  • Red Hat OpenStack Platform
  • Red Hat Virtualization
  • Red Hat Single Sign-On
  • Red Hat 3scale API Management

Mitigation

For Log4j versions >=2.10
set the system property log4j2.formatMsgNoLookups or the environment variable LOG4J_FORMAT_MSG_NO_LOOKUPS to true

For Log4j versions >=2.7 and <=2.14.1
all PatternLayout patterns can be modified to specify the message converter as %m{nolookups} instead of just %m

For Log4j versions >=2.0-beta9 and <=2.10.0
remove the JndiLookup class from the classpath. For example: 

zip -q -d log4j-core-*.jar org/apache/logging/log4j/core/lookup/JndiLookup.class

On OpenShift 4 and in OpenShift Logging, the above mitigation can be applied by following the steps in this article: https://access.redhat.com/solutions/6578421

On OpenShift 3.11, mitigation to the affected Elasticsearch component can be applied by following the steps in this article: https://access.redhat.com/solutions/6578441

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score9.81010
Attack VectorNetworkNetworkNetwork
Attack ComplexityLowLowLow
Privileges RequiredNoneNoneNone
User InteractionNoneNoneNone
ScopeUnchangedChangedChanged
ConfidentialityHighHighHigh
Integrity ImpactHighHighHigh
Availability ImpactHighHighHigh

Vector

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

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

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

Understanding the Weakness (CWE)

CWE-20

Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)

An attacker could provide unexpected values and cause a program crash or arbitrary control of resource allocation, leading to excessive consumption of resources such as memory and CPU.

Confidentiality

Technical Impact: Read Memory; Read Files or Directories

An attacker could read confidential data if they are able to control resource references.

Integrity,Confidentiality,Availability

Technical Impact: Modify Memory; Execute Unauthorized Code or Commands

An attacker could use malicious input to modify data or possibly alter control flow in unexpected ways, including arbitrary command execution.

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