Description

An attacker exploits a weakness in input validation on the target by supplying a specially constructed path utilizing dot and slash characters for the purpose of obtaining access to arbitrary files or resources. An attacker modifies a known path on the target in order to reach material that is not available through intended channels. These attacks normally involve adding additional path separators (/ or \\) and/or dots (.), or encodings thereof, in various combinations in order to reach parent directories or entirely separate trees of the target's directory structure.

Attack Execution Flow

4

1

Step 1

Explore

[Fingerprinting of the operating system] In order to perform a valid path traversal, the adversary needs to know what the underlying OS is so that the proper file seperator is used.
Port mapping. Identify ports that the system is listening on, and attempt to identify inputs and protocol types on those ports.
TCP/IP Fingerprinting. The adversary uses various software to make connections or partial connections and observe idiosyncratic responses from the operating system. Using those responses, they attempt to guess the actual operating system.
Induce errors to find informative error messages

Attack Techniques

TCP/IP Fingerprinting. The adversary uses various software to make connections or partial connections and observe idiosyncratic responses from the operating system. Using those responses, they attempt to guess the actual operating system.
Port mapping. Identify ports that the system is listening on, and attempt to identify inputs and protocol types on those ports.
IT: Fingerprinting TCP/IP. L'avversario utilizza diversi software per stabilire connessioni o connessioni parziali e osservare risposte peculiari dal sistema operativo. Utilizzando tali risposte, cerca di indovinare il sistema operativo effettivo.
Induce errors to find informative error messages
IT: Fingerprinting TCP/IP. L'avversario utilizza diversi software per stabilire connessioni o connessioni parziali e osservare risposte peculiari dal sistema operativo. Utilizzando tali risposte, cerca di indovinare il sistema operativo effettivo.

2

Step 2

Explore

[Survey application] Using manual or automated means, an adversary will survey the target application looking for all areas where user input is taken to specify a file name or path.
Use a spidering tool to follow and record all links on a web page. Make special note of any links that include parameters in the URL.
Use a proxy tool to record all links visited during a manual traversal of a web application. Make special note of any links that include parameters in the URL. Manual traversal of this type is frequently necessary to identify forms that are GET method forms rather than POST forms.
Use a browser to manually explore a website and analyze how it is constructed. Many browser plug-ins are available to facilitate the analysis or automate the URL discovery.

Attack Techniques

Use a browser to manually explore a website and analyze how it is constructed. Many browser plug-ins are available to facilitate the analysis or automate the URL discovery.
Use a spidering tool to follow and record all links on a web page. Make special note of any links that include parameters in the URL.
IT: Utilizza un browser per esplorare manualmente un sito web e analizzare come è strutturato. Sono disponibili numerosi plugin per browser che facilitano l'analisi o automatizzano la scoperta degli URL.
Use a proxy tool to record all links visited during a manual traversal of a web application. Make special note of any links that include parameters in the URL. Manual traversal of this type is frequently necessary to identify forms that are GET method forms rather than POST forms.
IT: Utilizza un browser per esplorare manualmente un sito web e analizzare come è strutturato. Sono disponibili numerosi plugin per browser che facilitano l'analisi o automatizzano la scoperta degli URL.

3

Step 3

Experiment

[Attempt variations on input parameters] Using manual or automated means, an adversary attempts varying relative file path combinations on all found user input locations and observes the responses.
Provide '../' or '..\' at the beginning of any filename to traverse to the parent directory
Use a list of probe strings as path traversal payload. Different strings may be used for different platforms. Strings contain relative path sequences such as '../'.
Use a proxy tool to record results of manual input of relative path traversal probes in known URLs.

Attack Techniques

Provide "../" or "..\" at the beginning of any filename to traverse to the parent directory
Use a list of probe strings as path traversal payload. Different strings may be used for different platforms. Strings contain relative path sequences such as "../".
IT: Fornisci "../" o "..\" all'inizio di qualsiasi nome file per attraversare la directory padre
Use a proxy tool to record results of manual input of relative path traversal probes in known URLs.
IT: Fornisci "../" o "..\" all'inizio di qualsiasi nome file per attraversare la directory padre

4

Step 4

Exploit

[Access, modify, or execute arbitrary files.] An adversary injects path traversal syntax into identified vulnerable inputs to cause inappropriate reading, writing or execution of files. An adversary could be able to read directories or files which they are normally not allowed to read. The adversary could also access data outside the web document root, or include scripts, source code and other kinds of files from external websites. Once the adversary accesses arbitrary files, they could also modify files. In particular situations, the adversary could also execute arbitrary code or system commands.
Manipulate file and its path by injecting relative path sequences (e.g. '../').
Download files, modify files, or try to execute shell commands (with binary files).

Attack Techniques

Download files, modify files, or try to execute shell commands (with binary files).
Manipulate file and its path by injecting relative path sequences (e.g. "../").
IT: Scarica file, modifica file o tenta di eseguire comandi shell (con file binari).

Mitigations

6

Design: Input Validation. Assume That User Inputs Are Malicious. Utilize Strict Type, Character, And Encoding Enforcement

Implementation: Perform Input Validation For All Remote Content, Including Remote And User-Generated Content.

Implementation: Prefer Working Without User Input When Using File System Calls

Implementation: Use Indirect References Rather Than Actual File Names.

Implementation: Use Possible Permissions On File Access When Developing And Deploying Web Applications.

Implementation: Validate User Input By Only Accepting Known Good. Ensure All Content That Is Delivered To Client Is Sanitized Against An Acceptable Content Specification -- Using An Allowlist Approach.

Consequences

Security Scopes Affected

Access Control Availability Confidentiality Integrity

Potential Impacts

Bypass Protection Mechanism Execute Unauthorized Commands Modify Data Read Data Unreliable Execution

CAPEC 139 Relative Path Traversal

Description

Attack Execution Flow

Step 1

Attack Techniques

Step 2

Attack Techniques

Step 3

Attack Techniques

Step 4

Attack Techniques

Mitigations

Design: Input Validation. Assume That User Inputs Are Malicious. Utilize Strict Type, Character, And Encoding Enforcement

Implementation: Perform Input Validation For All Remote Content, Including Remote And User-Generated Content.

Implementation: Prefer Working Without User Input When Using File System Calls

Implementation: Use Indirect References Rather Than Actual File Names.

Implementation: Use Possible Permissions On File Access When Developing And Deploying Web Applications.

Implementation: Validate User Input By Only Accepting Known Good. Ensure All Content That Is Delivered To Client Is Sanitized Against An Acceptable Content Specification -- Using An Allowlist Approach.

Consequences

Security Scopes Affected

Potential Impacts

Relationships

Parent CAPECs

CAPEC 139 Relative Path Traversal

Description

Attack Execution Flow

Step 1

Attack Techniques

Step 2

Attack Techniques

Step 3

Attack Techniques

Step 4

Attack Techniques

Mitigations

Design: Input Validation. Assume That User Inputs Are Malicious. Utilize Strict Type, Character, And Encoding Enforcement

Implementation: Perform Input Validation For All Remote Content, Including Remote And User-Generated Content.

Implementation: Prefer Working Without User Input When Using File System Calls

Implementation: Use Indirect References Rather Than Actual File Names.

Implementation: Use Possible Permissions On File Access When Developing And Deploying Web Applications.

Implementation: Validate User Input By Only Accepting Known Good. Ensure All Content That Is Delivered To Client Is Sanitized Against An Acceptable Content Specification -- Using An Allowlist Approach.

Consequences

Security Scopes Affected

Potential Impacts

Relationships

Parent CAPECs

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