CWE-32 路径遍历:'...' (三个点号)

Path Traversal: '...' (Triple Dot)

结构: Simple

Abstraction: Variant

状态: Incomplete

被利用可能性: unkown

基本描述

The software uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize '...' (triple dot) sequences that can resolve to a location that is outside of that directory.

扩展描述

This allows attackers to traverse the file system to access files or directories that are outside of the restricted directory.

The '...' manipulation is useful for bypassing some path traversal protection schemes. On some Windows systems, it is equivalent to "...." and might bypass checks that assume only two dots are valid. Incomplete filtering, such as removal of "./" sequences, can ultimately produce valid ".." sequences due to a collapse into unsafe value (CWE-182).

相关缺陷

  • cwe_Nature: ChildOf cwe_CWE_ID: 23 cwe_View_ID: 1000 cwe_Ordinal: Primary

  • cwe_Nature: ChildOf cwe_CWE_ID: 23 cwe_View_ID: 699 cwe_Ordinal: Primary

适用平台

Language: {'cwe_Class': 'Language-Independent', 'cwe_Prevalence': 'Undetermined'}

常见的影响

范围 影响 注释
['Confidentiality', 'Integrity'] ['Read Files or Directories', 'Modify Files or Directories']

可能的缓解方案

MIT-5.1 Implementation

策略: Input Validation

Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a whitelist 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 (i.e., do not rely on a blacklist). A blacklist 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, blacklists 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 whitelists 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 whitelist 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 blacklist, 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.

MIT-20 Implementation

策略: Input Validation

Inputs 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 whitelist validation schemes by introducing dangerous inputs after they have been checked.

分析过的案例

标识 说明 链接
CVE-2001-0467 "..." in web server https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2001-0467
CVE-2001-0615 "..." or "...." in chat server https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2001-0615
CVE-2001-0963 "..." in cd command in FTP server https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2001-0963
CVE-2001-1193 "..." in cd command in FTP server https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2001-1193
CVE-2001-1131 "..." in cd command in FTP server https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2001-1131
CVE-2001-0480 read of arbitrary files and directories using GET or CD with "..." in Windows-based FTP server. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2001-0480
CVE-2002-0288 read files using "." and Unicode-encoded "/" or "\" characters in the URL. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2002-0288
CVE-2003-0313 Directory listing of web server using "..." https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0313
CVE-2005-1658 Triple dot https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-1658

Notes

分类映射

映射的分类名 ImNode ID Fit Mapped Node Name
PLOVER '...' (triple dot)
Software Fault Patterns SFP16 Path Traversal