log4j2-scan is a single binary command-line tool for CVE-2021-44228 vulnerability scanning and mitigation patch. It also supports nested JAR file scanning and patch. It also detects CVE-2021-45046 (log4j 2.15.0), CVE-2021-45105 (log4j 2.16.0), CVE-2021-4104 (log4j 1.x), and CVE-2021-42550 (logback 0.9-1.2.7) vulnerabilities.
- log4j2-scan 2.4.0 (Windows x64, 7z)
- log4j2-scan 2.4.0 (Windows x64, zip)
- If you get
VCRUNTIME140.dll not founderror, install Visual C++ Redistributable. - If native executable doesn't work, use the JAR instead. 32bit is not supported.
- 7zip is available from www.7zip.org, and is open source and free.
- If you get
- log4j2-scan 2.4.0 (Linux x64)
- log4j2-scan 2.4.0 (Linux aarch64)
- If native executable doesn't work, use the JAR instead. 32bit is not supported.
- log4j2-scan 2.4.0 (Mac OS)
- log4j2-scan 2.4.0 (Any OS, 20KB)
Just run log4j2-scan.exe or log4j2-scan with target directory path. The logpresso-log4j2-scan.jar should work with JRE/JDK 7+
Usage
Logpresso CVE-2021-44228 Vulnerability Scanner 2.4.0 (2021-12-21)
Usage: log4j2-scan [--scan-log4j1] [--fix] target_path1 target_path2
-f [config_file_path]
Specify config file path which contains scan target paths.
Paths should be separated by new line. Prepend # for comment.
--scan-log4j1
Enables scanning for log4j 1 versions.
--scan-logback
Enables scanning for logback CVE-2021-42550.
--scan-zip
Scan also .zip extension files. This option may slow down scanning.
--zip-charset
Specify an alternate zip encoding other than utf-8. System default charset is used if not specified.
--fix
Backup original file and remove JndiLookup.class from JAR recursively.
With --scan-log4j1 option, it also removes JMSAppender.class, SocketServer.class, SMTPAppender.class, SMTPAppender$1.class
--force-fix
Do not prompt confirmation. Don't use this option unless you know what you are doing.
--all-drives
Scan all drives on Windows
--drives c,d
Scan specified drives on Windows. Spaces are not allowed here.
--no-symlink
Do not detect symlink as vulnerable file.
--exclude [path_prefix]
Exclude specified paths. You can specify multiple --exclude [path_prefix] pairs
--exclude-config [config_file_path]
Specify exclude path list in text file. Paths should be separated by new line. Prepend # for comment.
--exclude-pattern [pattern]
Exclude specified paths by pattern. You can specify multiple --exclude-pattern [pattern] pairs (non regex)
--exclude-fs nfs,tmpfs
Exclude paths by file system type. nfs, nfs3, nfs4, cifs, tmpfs, devtmpfs, fuse.sshfs and iso9660 is ignored by default.
--report-csv
Generate log4j2_scan_report_yyyyMMdd_HHmmss.csv in working directory if not specified otherwise via --report-path [path]
--report-json
Generate log4j2_scan_report_yyyyMMdd_HHmmss.json in working directory if not specified otherwise via --report-path [path]
--report-path
Specify report output path including filename. Implies --report-csv.
--report-dir
Specify report output directory. Implies --report-csv.
--no-empty-report
Do not generate empty report.
--old-exit-code
Return sum of vulnerable and potentially vulnerable files as exit code.
--debug
Print exception stacktrace for debugging.
--trace
Print all directories and files while scanning.
--silent
Do not print anything until scan is completed.
--help
Print this help.
On Windows
log4j2-scan [--fix] target_path
On Linux
./log4j2-scan [--fix] target_path
On UNIX (AIX, Solaris, and so on)
java -jar logpresso-log4j2-scan-2.4.0.jar [--fix] target_path
If you add --fix option, this program will copy vulnerable original JAR file to .bak file, and create new JAR file without org/apache/logging/log4j/core/lookup/JndiLookup.class entry. In most environments, JNDI lookup feature will not be used. However, you must use this option at your own risk. Depending the Operating System:
- Windows: It is necessary to shutdown any running JVM process before applying patch due to lock files. Start affected JVM process after fix.
- Linux/macOS: Apply patch, restart the JVM after
If you want to automate patch job, use --force-fix option. With this option, this program will no longer prompt for confirmation.
(mitigated) tag will be displayed if org/apache/logging/log4j/core/lookup/JndiLookup.class entry is removed from JAR file.
If you add --trace option, this program will print all visited directories and files. Use this option only for debugging.
On Windows:
CMD> log4j2-scan.exe D:\tmp
[*] Found CVE-2021-44228 vulnerability in D:\tmp\elasticsearch-7.16.0\bin\elasticsearch-sql-cli-7.16.0.jar, log4j 2.11.1
[*] Found CVE-2021-44228 vulnerability in D:\tmp\elasticsearch-7.16.0\lib\log4j-core-2.11.1.jar, log4j 2.11.1
[*] Found CVE-2021-44228 vulnerability in D:\tmp\flink-1.14.0\lib\log4j-core-2.14.1.jar, log4j 2.14.1
[*] Found CVE-2021-44228 vulnerability in D:\tmp\logstash-7.16.0\logstash-core\lib\jars\log4j-core-2.14.0.jar, log4j 2.14.0
[*] Found CVE-2021-44228 vulnerability in D:\tmp\logstash-7.16.0\vendor\bundle\jruby\2.5.0\gems\logstash-input-tcp-6.2.1-java\vendor\jar-dependencies\org\logstash\inputs\logstash-input-tcp\6.2.1\logstash-input-tcp-6.2.1.jar, log4j 2.9.1
[*] Found CVE-2021-44228 vulnerability in D:\tmp\solr-7.7.3\solr-7.7.3\contrib\prometheus-exporter\lib\log4j-core-2.11.0.jar, log4j 2.11.0
[*] Found CVE-2021-44228 vulnerability in D:\tmp\solr-7.7.3\solr-7.7.3\server\lib\ext\log4j-core-2.11.0.jar, log4j 2.11.0
[*] Found CVE-2021-44228 vulnerability in D:\tmp\solr-8.11.0\contrib\prometheus-exporter\lib\log4j-core-2.14.1.jar, log4j 2.14.1
[*] Found CVE-2021-44228 vulnerability in D:\tmp\solr-8.11.0\server\lib\ext\log4j-core-2.14.1.jar, log4j 2.14.1
Scanned 5047 directories and 26251 files
Found 9 vulnerable files
Completed in 0.42 seconds
Run in 5 steps:
- Find all .jar, .war, .ear, .aar, .rar, .nar files recursively.
- Find
META-INF/maven/org.apache.logging.log4j/log4j-core/pom.propertiesentry from JAR file. - Read groupId, artifactId, and version.
- Compare log4j2 version and print vulnerable version.
- If --fix option is used, backup vulnerable file and patch it.
- For example, original vulnerable.jar is copied to vulnerable.jar.bak
- -1 failed to run
- 0 for clean (No vulnerability)
- 1 for found
- 2 for some errors
If you have any question or issue, create an issue in this repository.