CVE-2021-44228

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.

Summary

Log4j versions prior to 2.16.0 are subject to a remote code execution vulnerability via the ldap JNDI parser. As per Apache's Log4j security guide: Apache Log4j2 <=2.14.1 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 2.16.0, this behavior has been disabled by default.

Log4j version 2.15.0 contained an earlier fix for the vulnerability, but that patch did not disable attacker-controlled JNDI lookups in all situations. For more information, see the Updated advice for version 2.16.0 section of this advisory.

Impact

Logging untrusted or user controlled data with a vulnerable version of Log4J may result in Remote Code Execution (RCE) against your application. This includes untrusted data included in logged errors such as exception traces, authentication failures, and other unexpected vectors of user controlled input.

Affected versions

Any Log4J version prior to v2.15.0 is affected to this specific issue.

The v1 branch of Log4J which is considered End Of Life (EOL) is vulnerable to other RCE vectors so the recommendation is to still update to 2.16.0 where possible.

Security releases

Additional backports of this fix have been made available in versions 2.3.1, 2.12.2, and 2.12.3

Affected packages

Only the org.apache.logging.log4j:log4j-core package is directly affected by this vulnerability. The org.apache.logging.log4j:log4j-api should be kept at the same version as the org.apache.logging.log4j:log4j-core package to ensure compatability if in use.

Remediation Advice

Updated advice for version 2.16.0

The Apache Logging Services team provided updated mitigation advice upon the release of version 2.16.0, which disables JNDI by default and completely removes support for message lookups. Even in version 2.15.0, lookups used in layouts to provide specific pieces of context information will still recursively resolve, possibly triggering JNDI lookups. This problem is being tracked as CVE-2021-45046. More information is available on the GitHub Security Advisory for CVE-2021-45046.

Users who want to avoid attacker-controlled JNDI lookups but cannot upgrade to 2.16.0 must ensure that no such lookups resolve to attacker-provided data and ensure that the the JndiLookup class is not loaded.

Please note that Log4J v1 is End Of Life (EOL) and will not receive patches for this issue. Log4J v1 is also vulnerable to other RCE vectors and we recommend you migrate to Log4J 2.16.0 where possible.

Java logging package.

Security Fix(es):

The details of a high-risk vulnerability in Apache Log4j2 have been disclosed. Attackers can use the vulnerability to execute code remotely. Some reports carry suspected POC; Apache Log4j2 is a Java-based logging tool. This tool rewrites the Log4j framework and introduces a large number of rich features. The log framework is widely used in business system development to record log information. In most cases, developers may write error messages caused by user input into the log. The trigger condition of this vulnerability is that as long as the data input by external users will be recorded in the log, it can cause remote code execution.(CVE-2021-44228)

Log4j is a tool to help the programmer output log statements to a variety of output targets.

Security Fix(es):

Apache Log4j2 versions 2.0-alpha1 through 2.16.0 (excluding 2.12.3) did not protect from uncontrolled recursion from self-referential lookups. This allows an attacker with control over Thread Context Map data to cause a denial of service when a crafted string is interpreted. This issue was fixed in Log4j 2.17.0 and 2.12.3.(CVE-2021-45105) It was found that the fix to address CVE-2021-44228 in Apache Log4j 2.15.0 was incomplete in certain non-default configurations. This could allows attackers with control over Thread Context Map (MDC) input data when the logging configuration uses a non-default Pattern Layout with either a Context Lookup (for example, $${ctx:loginId}) or a Thread Context Map pattern (%X, %mdc, or %MDC) to craft malicious input data using a JNDI Lookup pattern resulting in a denial of service (DOS) attack. Log4j 2.15.0 makes a best-effort attempt to restrict JNDI LDAP lookups to localhost by default. Log4j 2.16.0 fixes this issue by removing support for message lookup patterns and disabling JNDI functionality by default.(CVE-2021-45046) The details of a high-risk vulnerability in Apache Log4j2 have been disclosed. Attackers can use the vulnerability to execute code remotely. Some reports carry suspected POC, Apache Log4j2 is a Java-based logging tool. This tool rewrites the Log4j framework and introduces a large number of rich features. The log framework is widely used in business system development to record log information. In most cases, developers may write error messages caused by user input into the log. The trigger condition of this vulnerability is that as long as the data input by external users will be recorded in the log, it can cause remote code execution.(CVE-2021-44228)

Apache Flink is a framework and distributed processing engine for stateful computations over unbounded and bounded data streams. Flink has been designed to run in all common cluster environments, perform computations at in-memory speed and at any scale.

Security Fix(es):

Apache Log4j2 2.0-beta9 through 2.12.1 and 2.13.0 through 2.15.0 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, 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.(CVE-2021-44228)

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.

TuxCare rebuilt org.apache.logging.log4j:log4j-core to address 3 CVEs. Fixed in 2.11.0-tuxcare.2.

TuxCare rebuilt org.apache.logging.log4j:log4j-core to address 3 CVEs. Fixed in 2.5-tuxcare.2.

TuxCare rebuilt 2 org.apache.logging.log4j packages to address 2 CVEs. Fixed in 2.10.0-tuxcare.2.

TuxCare rebuilt org.apache.logging.log4j:log4j-core to address 1 CVE. Fixed in 2.7-tuxcare.3.

TuxCare rebuilt org.apache.logging.log4j:log4j-core to address 1 CVE. Fixed in 2.9.1-tuxcare.3.

TuxCare rebuilt org.apache.logging.log4j:log4j-core to address 1 CVE. Fixed in 2.8.2-tuxcare.3.

Apache Log4j2 <=2.14.1 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. (CVE-2021-44228)

This update for log4j fixes the following issues:

• CVE-2021-44228: Fix a remote code execution vulnerability that existed in the LDAP JNDI parser. [bsc#1193611, CVE-2021-44228]

This update was imported from the SUSE:SLE-15-SP2:Update update project.

This update for log4j fixes the following issue:

CVE-2021-44228: The previously published fix by upstream turned out to be incomplete. Therefore, upstream has recommended disabling JNDI support in log4j by default to be completely sure that this vulnerability cannot be exploited. This update implements that recommendation and disables JNDI support by default. [bsc#1193611, CVE-2021-44228]

This update was imported from the SUSE:SLE-15-SP2:Update update project.

This update for log4j fixes the following issue:

• Previously published fixes for log4jshell turned out to be incomplete. Upstream has followed up on the original patch for CVE-2021-44228 with several additional changes (LOG4J2-3198, LOG4J2-3201, LOG4J2-3208, and LOG4J2-3211) that are included in this update. Since the totality of those patches is pretty much equivalent to an update to the latest version of log4j, we did update the package's tarball from version 2.13.0 to 2.16.0 instead of trying to apply those patches to the old version. This change brings in a new dependency on 'jakarta-servlet' and a version update of 'disruptor'. [bsc#1193743, CVE-2021-45046]

This update was imported from SUSE:SLE-15-SP2:Update.

This update for logback fixes the following issues:

Upgrade to version 1.2.8

• In response to log4Shell/CVE-2021-44228, all JNDI lookup code in logback has been disabled until further notice. This impacts ContextJNDISelector and insertFromJNDI element in configuration files.
• Also in response to log4Shell/CVE-2021-44228, all database (JDBC) related code in the project has been removed with no replacement.
• Note that the vulnerability mentioned in LOGBACK-1591 requires write access to logback's configuration file as a prerequisite. The log4Shell/CVE-2021-44228 and LOGBACK-1591 are of different severity levels. A successful RCE requires all of the following conditions to be met:
  • write access to logback.xml
  • use of versions lower then 1.2.8
  • reloading of poisoned configuration data, which implies application restart or scan='true' set prior to attack

This update was imported from the SUSE:SLE-15-SP2:Update update project.

This update for log4j fixes the following issues:

• CVE-2021-44228: Fix a remote code execution vulnerability that existed in the LDAP JNDI parser. [bsc#1193611, CVE-2021-44228]

This update for log4j fixes the following issue:

CVE-2021-44228: The previously published fix by upstream turned out to be incomplete. Therefore, upstream has recommended disabling JNDI support in log4j by default to be completely sure that this vulnerability cannot be exploited.

This update implements that recommendation and disables JNDI support by default. [bsc#1193611, CVE-2021-44228]

CVE-2021-45046: A Thread Context Message Pattern and Context Lookup Pattern vulnerable to a denial of service attack is also fixed by disabling JNDI support by default (bsc#1193743)

This update for log4j fixes the following issue:

• Previously published fixes for log4jshell turned out to be incomplete. Upstream has followed up on the original patch for CVE-2021-44228 with several additional changes (LOG4J2-3198, LOG4J2-3201, LOG4J2-3208, and LOG4J2-3211) that are included in this update. Since the totality of those patches is pretty much equivalent to an update to the latest version of log4j, we did update the package's tarball from version 2.13.0 to 2.16.0 instead of trying to apply those patches to the old version. This change brings in a new dependency on 'jakarta-servlet' and a version update of 'disruptor'. [bsc#1193743, CVE-2021-45046]

This update for logback fixes the following issues:

Upgrade to version 1.2.8

• In response to log4Shell/CVE-2021-44228, all JNDI lookup code in logback has been disabled until further notice. This impacts ContextJNDISelector and insertFromJNDI element in configuration files.
• Also in response to log4Shell/CVE-2021-44228, all database (JDBC) related code in the project has been removed with no replacement.
• Note that the vulnerability mentioned in LOGBACK-1591 requires write access to logback's configuration file as a prerequisite. The log4Shell/CVE-2021-44228 and LOGBACK-1591 are of different severity levels. A successful RCE requires all of the following conditions to be met:
  • write access to logback.xml
  • use of versions lower then 1.2.8
  • reloading of poisoned configuration data, which implies application restart or scan='true' set prior to attack

These are all security issues fixed in the log4j-2.13.2-2.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the logback-1.2.8-1.1 package on the GA media of openSUSE Tumbleweed.

This update for storm fixes the following issues:

• Remove JndiLookup from log4j 2.x jars during build to prevent 'log4shell' code injection. (bsc#1193641, bsc#1193611, CVE-2021-44228)
• Remove JMSAppender from log4j 1.2.x jars during build to prevent attacks when JMS is enabled (bsc#1193641, bsc#1193662, CVE-2021-4104)

This update for storm-kit fixes the following issues:

• Remove JndiLookup from log4j 2.x jars during build to prevent 'log4shell' code injection. (bsc#1193641, bsc#1193611, CVE-2021-44228)
• Remove JMSAppender from log4j 1.2.x jars during build to prevent attacks when JMS is enabled (bsc#1193641, bsc#1193662, CVE-2021-4104)

Chen Zhaojun discovered that Apache Log4j 2 allows remote attackers to run programs via a special crafted input. An attacker could use this vulnerability to cause a denial of service or possibly execute arbitrary code. Please see the following link for more information: https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/Log4Shell

USN-5192-1 fixed a vulnerability in Apache Log4j 2. This update provides the corresponding update for Ubuntu 16.04 ESM.

Original advisory details:

Chen Zhaojun discovered that Apache Log4j 2 allows remote attackers to run programs via a special crafted input. An attacker could use this vulnerability to cause a denial of service or possibly execute arbitrary code.

It was found that the fix to address CVE-2021-44228 in Apache Log4j 2.15.0 was incomplete in certain non-default configurations. An attacker could use this vulnerability to cause a denial of service. Please see the following link for more information: https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/Log4Shell