[![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/cwe_logo.jpg]] Common Weakness Enumeration A Community-Developed List of Software & Hardware Weakness Types](https://cwe.mitre.org/index.html) Home > CWE List > CWE- Individual Dictionary Definition (4.8) ID Lookup: Home https://cwe.mitre.org/about/index.html https://cwe.mitre.org/data/index.html https://cwe.mitre.org/scoring/index.html https://cwe.mitre.org/documents/cwe_usage/guidance.html https://cwe.mitre.org/community/index.html https://cwe.mitre.org/news/index.html Search CWE-22: Improper Limitation of a Pathname to a Restricted Directory (‘Path Traversal’) Weakness ID: 22 Abstraction: BaseStructure: Simple Presentation Filter: [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Description The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Extended Description Many file operations are intended to take place within a restricted directory. By using special elements such as “..” and “/” separators, attackers can escape outside of the restricted location to access files or directories that are elsewhere on the system. One of the most common special elements is the “../” sequence, which in most modern operating systems is interpreted as the parent directory of the current location. This is referred to as relative path traversal. Path traversal also covers the use of absolute pathnames such as “/usr/local/bin”, which may also be useful in accessing unexpected files. This is referred to as absolute path traversal. In many programming languages, the injection of a null byte (the 0 or NUL) may allow an attacker to truncate a generated filename to widen the scope of attack. For example, the software may add “.txt” to any pathname, thus limiting the attacker to text files, but a null injection may effectively remove this restriction. [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Alternate Terms Directory traversal Path traversal: “Path traversal” is preferred over “directory traversal,” but both terms are attack-focused. [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Relationships ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/dictionary.gif]] [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Relevant to the view “Research Concepts” (CWE-1000) Nature Type ID Name ChildOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/class.gif]] 668 Exposure of Resource to Wrong Sphere ChildOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/class.gif]] 706 Use of Incorrectly-Resolved Name or Reference ParentOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/base.gif]] 23 Relative Path Traversal ParentOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/base.gif]] 36 Absolute Path Traversal CanFollow ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/class.gif]] 20 Improper Input Validation CanFollow ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/base.gif]] 73 External Control of File Name or Path CanFollow ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/class.gif]] 172 Encoding Error ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/dictionary.gif]] [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_less.gif]] Relevant to the view “Weaknesses for Simplified Mapping of Published Vulnerabilities” (CWE-1003) ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/dictionary.gif]] [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_less.gif]] Relevant to the view “CISQ Quality Measures (2020)” (CWE-1305) ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/dictionary.gif]] [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_less.gif]] Relevant to the view “CISQ Data Protection Measures” (CWE-1340) [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Modes Of Introduction ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/dictionary.gif]] Phase Note Architecture and Design Implementation [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Applicable Platforms ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/dictionary.gif]] Languages Class: Language-Independent (Undetermined Prevalence) [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Common Consequences ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/dictionary.gif]] Scope Impact Likelihood IntegrityConfidentialityAvailability Technical Impact: Execute Unauthorized Code or CommandsThe attacker may be able to create or overwrite critical files that are used to execute code, such as programs or libraries. Integrity Technical Impact: Modify Files or DirectoriesThe attacker may be able to overwrite or create critical files, such as programs, libraries, or important data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, appending a new account at the end of a password file may allow an attacker to bypass authentication. Confidentiality Technical Impact: Read Files or DirectoriesThe attacker may be able read the contents of unexpected files and expose sensitive data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, by reading a password file, the attacker could conduct brute force password guessing attacks in order to break into an account on the system. Availability Technical Impact: DoS: Crash, Exit, or RestartThe attacker may be able to overwrite, delete, or corrupt unexpected critical files such as programs, libraries, or important data. This may prevent the software from working at all and in the case of a protection mechanisms such as authentication, it has the potential to lockout every user of the software. [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Likelihood Of Exploit High [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Demonstrative Examples Example 1 The following code could be for a social networking application in which each user’s profile information is stored in a separate file. All files are stored in a single directory. (bad code) Example Language: Perl my $dataPath = “/users/cwe/profiles”;my $username = param(“user”);my $profilePath = $dataPath . “/” . $username;open(my $fh, “<$profilePath”) || ExitError(“profile read error: $profilePath”);print “n”;while (<$fh>) { print “$_n”; }print “n”; While the programmer intends to access files such as “/users/cwe/profiles/alice” or “/users/cwe/profiles/bob”, there is no verification of the incoming user parameter. An attacker could provide a string such as: (attack code) ../../../etc/passwd The program would generate a profile pathname like this: (result) /users/cwe/profiles/../../../etc/passwd When the file is opened, the operating system resolves the “../” during path canonicalization and actually accesses this file: (result) /etc/passwd As a result, the attacker could read the entire text of the password file. Notice how this code also contains an error message information leak (CWE-209) if the user parameter does not produce a file that exists: the full pathname is provided. Because of the lack of output encoding of the file that is retrieved, there might also be a cross-site scripting problem (CWE-79) if profile contains any HTML, but other code would need to be examined. Example 2 In the example below, the path to a dictionary file is read from a system property and used to initialize a File object. (bad code) Example Language: Java String filename = System.getProperty(“com.domain.application.dictionaryFile”);File dictionaryFile = new File(filename); However, the path is not validated or modified to prevent it from containing relative or absolute path sequences before creating the File object. This allows anyone who can control the system property to determine what file is used. Ideally, the path should be resolved relative to some kind of application or user home directory. Example 3 The following code takes untrusted input and uses a regular expression to filter “../” from the input. It then appends this result to the /home/user/ directory and attempts to read the file in the final resulting path. (bad code) Example Language: Perl my $Username = GetUntrustedInput();$Username =~ s/..///;my $filename = “/home/user/” . $Username;ReadAndSendFile($filename); Since the regular expression does not have the /g global match modifier, it only removes the first instance of “../” it comes across. So an input value such as: (attack code) ../../../etc/passwd will have the first “../” stripped, resulting in: (result) ../../etc/passwd This value is then concatenated with the /home/user/ directory: (result) /home/user/../../etc/passwd which causes the /etc/passwd file to be retrieved once the operating system has resolved the ../ sequences in the pathname. This leads to relative path traversal (CWE-23). Example 4 The following code attempts to validate a given input path by checking it against an allowlist and once validated delete the given file. In this specific case, the path is considered valid if it starts with the string “/safe_dir/”. (bad code) Example Language: Java String path = getInputPath();if (path.startsWith("/safe_dir/")){ File f = new File(path);f.delete() } An attacker could provide an input such as this: (attack code) /safe_dir/../important.dat The software assumes that the path is valid because it starts with the “/safe_path/” sequence, but the “../” sequence will cause the program to delete the important.dat file in the parent directory Example 5 The following code demonstrates the unrestricted upload of a file with a Java servlet and a path traversal vulnerability. The action attribute of an HTML form is sending the upload file request to the Java servlet. (good code) Example Language: HTML When submitted the Java servlet’s doPost method will receive the request, extract the name of the file from the Http request header, read the file contents from the request and output the file to the local upload directory. (bad code) Example Language: Java public class FileUploadServlet extends HttpServlet { …protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType(“text/html”);PrintWriter out = response.getWriter();String contentType = request.getContentType();// the starting position of the boundary headerint ind = contentType.indexOf(“boundary=”);String boundary = contentType.substring(ind+9);String pLine = new String();String uploadLocation = new String(UPLOAD_DIRECTORY_STRING); //Constant value// verify that content type is multipart form dataif (contentType != null && contentType.indexOf(“multipart/form-data”) != -1) { // extract the filename from the Http headerBufferedReader br = new BufferedReader(new InputStreamReader(request.getInputStream()));…pLine = br.readLine();String filename = pLine.substring(pLine.lastIndexOf(""), pLine.lastIndexOf("""));…// output the file to the local upload directorytry { BufferedWriter bw = new BufferedWriter(new FileWriter(uploadLocation+filename, true));for (String line; (line=br.readLine())!=null; ) { if (line.indexOf(boundary) == -1) { bw.write(line);bw.newLine();bw.flush(); } } //end of for loopbw.close(); } catch (IOException ex) {…}// output successful upload response HTML page }// output unsuccessful upload response HTML pageelse{…} } … } This code does not perform a check on the type of the file being uploaded (CWE-434). This could allow an attacker to upload any executable file or other file with malicious code. Additionally, the creation of the BufferedWriter object is subject to relative path traversal (CWE-23). Since the code does not check the filename that is provided in the header, an attacker can use “../” sequences to write to files outside of the intended directory. Depending on the executing environment, the attacker may be able to specify arbitrary files to write to, leading to a wide variety of consequences, from code execution, XSS (CWE-79), or system crash. [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Observed Examples Reference Description CVE-2021-21972 Chain: Cloud computing virtualization platform does not require authentication for upload of a tar format file (CWE-306), then uses .. path traversal sequences (CWE-23) in the file to access unexpected files, as exploited in the wild per CISA KEV. CVE-2020-3452 Chain: security product has improper input validation (CWE-20) leading to directory traversal (CWE-22), as exploited in the wild per CISA KEV. CVE-2010-0467 Newsletter module allows reading arbitrary files using “../” sequences. CVE-2009-4194 FTP server allows deletion of arbitrary files using “..” in the DELE command. CVE-2009-4053 FTP server allows creation of arbitrary directories using “..” in the MKD command. CVE-2009-0244 FTP service for a Bluetooth device allows listing of directories, and creation or reading of files using “..” sequences. CVE-2009-4013 Software package maintenance program allows overwriting arbitrary files using “../” sequences. CVE-2009-4449 Bulletin board allows attackers to determine the existence of files using the avatar. CVE-2009-4581 PHP program allows arbitrary code execution using “..” in filenames that are fed to the include() function. CVE-2010-0012 Overwrite of files using a .. in a Torrent file. CVE-2010-0013 Chat program allows overwriting files using a custom smiley request. CVE-2008-5748 Chain: external control of values for user’s desired language and theme enables path traversal. CVE-2009-1936 Chain: library file sends a redirect if it is directly requested but continues to execute, allowing remote file inclusion and path traversal. [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Potential Mitigations Phase: ImplementationStrategy: Input ValidationAssume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue."Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.When validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single “.” character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as “/” to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434.Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering “/” is insufficient protection if the filesystem also supports the use of "” as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if “../” sequences are removed from the “…/…//” string in a sequential fashion, two instances of “../” would be removed from the original string, but the remaining characters would still form the “../” string. Phase: Architecture and DesignFor any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server. Phase: ImplementationStrategy: Input ValidationInputs should be decoded and canonicalized to the application’s current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes “..” sequences and symbolic links (CWE-23, CWE-59). This includes:* realpath() in C* getCanonicalPath() in Java* GetFullPath() in ASP.NET* realpath() or abs_path() in Perl* realpath() in PHP Phase: Architecture and DesignStrategy: Libraries or FrameworksUse a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Phase: OperationStrategy: FirewallUse an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.Effectiveness: ModerateNote: An application firewall might not cover all possible input vectors. In addition, attack techniques might be available to bypass the protection mechanism, such as using malformed inputs that can still be processed by the component that receives those inputs. Depending on functionality, an application firewall might inadvertently reject or modify legitimate requests. Finally, some manual effort may be required for customization. Phases: Architecture and Design; OperationStrategy: Environment HardeningRun your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations. Phase: Architecture and DesignStrategy: Enforcement by ConversionWhen the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.For example, ID 1 could map to “inbox.txt” and ID 2 could map to “profile.txt”. Features such as the ESAPI AccessReferenceMap [REF-185] provide this capability. Phases: Architecture and Design; OperationStrategy: Sandbox or JailRun the code in a “jail” or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.Be careful to avoid CWE-243 and other weaknesses related to jails.Effectiveness: LimitedNote: The effectiveness of this mitigation depends on the prevention capabilities of the specific sandbox or jail being used and might only help to reduce the scope of an attack, such as restricting the attacker to certain system calls or limiting the portion of the file system that can be accessed. Phases: Architecture and Design; OperationStrategy: Attack Surface ReductionStore library, include, and utility files outside of the web document root, if possible. Otherwise, store them in a separate directory and use the web server’s access control capabilities to prevent attackers from directly requesting them. One common practice is to define a fixed constant in each calling program, then check for the existence of the constant in the library/include file; if the constant does not exist, then the file was directly requested, and it can exit immediately.This significantly reduces the chance of an attacker being able to bypass any protection mechanisms that are in the base program but not in the include files. It will also reduce the attack surface. Phase: ImplementationEnsure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.In the context of path traversal, error messages which disclose path information can help attackers craft the appropriate attack strings to move through the file system hierarchy. Phases: Operation; ImplementationStrategy: Environment HardeningWhen using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues. [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Weakness Ordinalities Ordinality Description Primary (where the weakness exists independent of other weaknesses) Resultant (where the weakness is typically related to the presence of some other weaknesses) [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Detection Methods Automated Static AnalysisAutomated techniques can find areas where path traversal weaknesses exist. However, tuning or customization may be required to remove or de-prioritize path-traversal problems that are only exploitable by the software’s administrator - or other privileged users - and thus potentially valid behavior or, at worst, a bug instead of a vulnerability.Effectiveness: High Manual Static AnalysisManual white box techniques may be able to provide sufficient code coverage and reduction of false positives if all file access operations can be assessed within limited time constraints.Effectiveness: High Automated Static Analysis - Binary or BytecodeAccording to SOAR, the following detection techniques may be useful:Highly cost effective:* Bytecode Weakness Analysis - including disassembler + source code weakness analysisCost effective for partial coverage:* Binary Weakness Analysis - including disassembler + source code weakness analysisEffectiveness: High Manual Static Analysis - Binary or BytecodeAccording to SOAR, the following detection techniques may be useful:Cost effective for partial coverage:* Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomaliesEffectiveness: SOAR Partial Dynamic Analysis with Automated Results InterpretationAccording to SOAR, the following detection techniques may be useful:Highly cost effective:* Web Application Scanner* Web Services Scanner* Database ScannersEffectiveness: High Dynamic Analysis with Manual Results InterpretationAccording to SOAR, the following detection techniques may be useful:Highly cost effective:* Fuzz Tester* Framework-based FuzzerEffectiveness: High Manual Static Analysis - Source CodeAccording to SOAR, the following detection techniques may be useful:Highly cost effective:* Manual Source Code Review (not inspections)Cost effective for partial coverage:* Focused Manual Spotcheck - Focused manual analysis of sourceEffectiveness: High Automated Static Analysis - Source CodeAccording to SOAR, the following detection techniques may be useful:Highly cost effective:* Source code Weakness Analyzer* Context-configured Source Code Weakness AnalyzerEffectiveness: High Architecture or Design ReviewAccording to SOAR, the following detection techniques may be useful:Highly cost effective:* Formal Methods / Correct-By-ConstructionCost effective for partial coverage:* Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)Effectiveness: High [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Functional Areas File Processing [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Affected Resources File or Directory [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Memberships ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/dictionary.gif]] Nature Type ID Name MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/view.gif]] 635 Weaknesses Originally Used by NVD from 2008 to 2016 MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 715 OWASP Top Ten 2007 Category A4 - Insecure Direct Object Reference MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 723 OWASP Top Ten 2004 Category A2 - Broken Access Control MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 743 CERT C Secure Coding Standard (2008) Chapter 10 - Input Output (FIO) MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 802 2010 Top 25 - Risky Resource Management MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 813 OWASP Top Ten 2010 Category A4 - Insecure Direct Object References MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 865 2011 Top 25 - Risky Resource Management MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 877 CERT C++ Secure Coding Section 09 - Input Output (FIO) MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/view.gif]] 884 CWE Cross-section MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 932 OWASP Top Ten 2013 Category A4 - Insecure Direct Object References MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 981 SFP Secondary Cluster: Path Traversal MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 1031 OWASP Top Ten 2017 Category A5 - Broken Access Control MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 1131 CISQ Quality Measures (2016) - Security MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 1179 SEI CERT Perl Coding Standard - Guidelines 01. Input Validation and Data Sanitization (IDS) MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/view.gif]] 1200 Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 1308 CISQ Quality Measures - Security MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/view.gif]] 1337 Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/view.gif]] 1340 CISQ Data Protection Measures MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/category.gif]] 1345 OWASP Top Ten 2021 Category A01:2021 - Broken Access Control MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/view.gif]] 1350 Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses MemberOf ![[./resources/cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources/view.gif]] 1387 Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Notes Relationship Pathname equivalence can be regarded as a type of canonicalization error. Relationship Some pathname equivalence issues are not directly related to directory traversal, rather are used to bypass security-relevant checks for whether a file/directory can be accessed by the attacker (e.g. a trailing “/” on a filename could bypass access rules that don’t expect a trailing /, causing a server to provide the file when it normally would not). Research Gap Many variants of path traversal attacks are probably under-studied with respect to root cause. CWE-790 and CWE-182 begin to cover part of this gap. Research Gap Incomplete diagnosis or reporting of vulnerabilities can make it difficult to know which variant is affected. For example, a researcher might say that “..” is vulnerable, but not test “../” which may also be vulnerable. Any combination of directory separators ("/", “”, etc.) and numbers of “.” (e.g. “….”) can produce unique variants; for example, the “//../” variant is not listed (CVE-2004-0325). See this entry’s children and lower-level descendants. Terminology Like other weaknesses, terminology is often based on the types of manipulations used, instead of the underlying weaknesses. Some people use “directory traversal” only to refer to the injection of “..” and equivalent sequences whose specific meaning is to traverse directories. Other variants like “absolute pathname” and “drive letter” have the *effect* of directory traversal, but some people may not call it such, since it doesn’t involve “..” or equivalent. [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Taxonomy Mappings Mapped Taxonomy Name Node ID Fit Mapped Node Name PLOVER Path Traversal OWASP Top Ten 2007 A4 CWE More Specific Insecure Direct Object Reference OWASP Top Ten 2004 A2 CWE More Specific Broken Access Control CERT C Secure Coding FIO02-C Canonicalize path names originating from untrusted sources SEI CERT Perl Coding Standard IDS00-PL Exact Canonicalize path names before validating them WASC 33 Path Traversal Software Fault Patterns SFP16 Path Traversal OMG ASCSM ASCSM-CWE-22 [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Related Attack Patterns CAPEC-ID Attack Pattern Name CAPEC-126 Path Traversal CAPEC-64 Using Slashes and URL Encoding Combined to Bypass Validation Logic CAPEC-76 Manipulating Web Input to File System Calls CAPEC-78 Using Escaped Slashes in Alternate Encoding CAPEC-79 Using Slashes in Alternate Encoding [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] References [REF-7] Michael Howard and David LeBlanc. “Writing Secure Code”. Chapter 11, “Directory Traversal and Using Parent Paths (..)” Page 370. 2nd Edition. Microsoft Press. 2002-12-04. «https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>>. [REF-45] OWASP. “OWASP Enterprise Security API (ESAPI) Project”. «http://www.owasp.org/index.php/ESAPI>>. [REF-185] OWASP. “Testing for Path Traversal (OWASP-AZ-001)”. «http://www.owasp.org/index.php/Testing_for_Path_Traversal_(OWASP-AZ-001)>>. [REF-186] Johannes Ullrich. “Top 25 Series - Rank 7 - Path Traversal”. SANS Software Security Institute. 2010-03-09. «http://blogs.sans.org/appsecstreetfighter/2010/03/09/top-25-series-rank-7-path-traversal/>>. [REF-76] Sean Barnum and Michael Gegick. “Least Privilege”. 2005-09-14. «https://buildsecurityin.us-cert.gov/daisy/bsi/articles/knowledge/principles/351.html>>. [REF-62] Mark Dowd, John McDonald and Justin Schuh. “The Art of Software Security Assessment”. Chapter 9, “Filenames and Paths”, Page 503. 1st Edition. Addison Wesley. 2006. [REF-962] Object Management Group (OMG). “Automated Source Code Security Measure (ASCSM)”. ASCSM-CWE-22. 2016-01. «http://www.omg.org/spec/ASCSM/1.0/>>. [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Content History [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_more.gif]] Submissions Submission Date Submitter Organization 2006-07-19 PLOVER [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_less.gif]] Modifications — — — [[#|!._resources_cwe-cwe-22-improper-limitation-of-a-pathname-to-a-.resources_head_less.gif]] Previous Entry Names — — — **Page Last Updated:** June 28, 2022 Site Map | Terms of Use | Privacy Policy | Contact Us | Use of the Common Weakness Enumeration (CWE) and the associated references from this website are subject to the Terms of Use. 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