Read Time:11 Second
Description
This weakness has been deprecated because it was a duplicate of CWE-493. All content has been transferred to CWE-493.
Modes of Introduction:
Related Weaknesses
Consequences
Category Archives: CWE
CWE-219 – Storage of File with Sensitive Data Under Web Root
Read Time:53 Second
Description
The application stores sensitive data under the web document root with insufficient access control, which might make it accessible to untrusted parties.
Besides public-facing web pages and code, applications may store sensitive data, code that is not directly invoked, or other files under the web document root of the web server. If the server is not configured or otherwise used to prevent direct access to those files, then attackers may obtain this sensitive data.
Modes of Introduction:
– Operation
Related Weaknesses
Consequences
Confidentiality: Read Application Data
Potential Mitigations
Phase: Implementation, System Configuration
Description:
Avoid storing information under the web root directory.
Phase: System Configuration
Description:
Access control permissions should be set to prevent reading/writing of sensitive files inside/outside of the web directory.
CVE References
- CVE-2005-1835
- Data file under web root.
- CVE-2005-2217
- Data file under web root.
- CVE-2002-1449
- Username/password in data file under web root.
- CVE-2002-0943
- Database file under web root.
- CVE-2005-1645
- database file under web root.
CWE-179 – Incorrect Behavior Order: Early Validation
Read Time:1 Minute, 25 Second
Description
The software validates input before applying protection mechanisms that modify the input, which could allow an attacker to bypass the validation via dangerous inputs that only arise after the modification.
Software needs to validate data at the proper time, after data has been canonicalized and cleansed. Early validation is susceptible to various manipulations that result in dangerous inputs that are produced by canonicalization and cleansing.
Modes of Introduction:
– Implementation
Related Weaknesses
Consequences
Access Control, Integrity: Bypass Protection Mechanism, Execute Unauthorized Code or Commands
An attacker could include dangerous input that bypasses validation protection mechanisms which can be used to launch various attacks including injection attacks, execute arbitrary code or cause other unintended behavior.
Potential Mitigations
Phase: Implementation
Description:
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 allowlist validation schemes by introducing dangerous inputs after they have been checked.
CVE References
- CVE-2002-0433
- Product allows remote attackers to view restricted files via an HTTP request containing a “*” (wildcard or asterisk) character.
- CVE-2003-0332
- Product modifies the first two letters of a filename extension after performing a security check, which allows remote attackers to bypass authentication via a filename with a .ats extension instead of a .hts extension.
- CVE-2002-0802
- Database consumes an extra character when processing a character that cannot be converted, which could remove an escape character from the query and make the application subject to SQL injection attacks.
- CVE-2000-0191
- Overlaps “fakechild/../realchild”
- CVE-2004-2363
- Product checks URI for “
- CVE-2002-0934
- Directory traversal vulnerability allows remote attackers to read or modify arbitrary files via invalid characters between two . (dot) characters, which are filtered and result in a “..” sequence.
- CVE-2003-0282
- Directory traversal vulnerability allows attackers to overwrite arbitrary files via invalid characters between two . (dot) characters, which are filtered and result in a “..” sequence.
CWE-180 – Incorrect Behavior Order: Validate Before Canonicalize
Read Time:1 Minute, 8 Second
Description
The software validates input before it is canonicalized, which prevents the software from detecting data that becomes invalid after the canonicalization step.
This can be used by an attacker to bypass the validation and launch attacks that expose weaknesses that would otherwise be prevented, such as injection.
Modes of Introduction:
– Implementation
Related Weaknesses
Consequences
Access Control: Bypass Protection Mechanism
Potential Mitigations
Phase: Implementation
Description:
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 allowlist validation schemes by introducing dangerous inputs after they have been checked.
CVE References
- CVE-2002-0433
- Product allows remote attackers to view restricted files via an HTTP request containing a “*” (wildcard or asterisk) character.
- CVE-2003-0332
- Product modifies the first two letters of a filename extension after performing a security check, which allows remote attackers to bypass authentication via a filename with a .ats extension instead of a .hts extension.
- CVE-2002-0802
- Database consumes an extra character when processing a character that cannot be converted, which could remove an escape character from the query and make the application subject to SQL injection attacks.
- CVE-2000-0191
- Overlaps “fakechild/../realchild”
- CVE-2004-2363
- Product checks URI for “
CWE-181 – Incorrect Behavior Order: Validate Before Filter
Read Time:45 Second
Description
The software validates data before it has been filtered, which prevents the software from detecting data that becomes invalid after the filtering step.
This can be used by an attacker to bypass the validation and launch attacks that expose weaknesses that would otherwise be prevented, such as injection.
Modes of Introduction:
– Implementation
Related Weaknesses
Consequences
Access Control: Bypass Protection Mechanism
Potential Mitigations
Phase: Implementation, Architecture and Design
Description:
Inputs should be decoded and canonicalized to the application’s current internal representation before being filtered.
CVE References
- CVE-2002-0934
- Directory traversal vulnerability allows remote attackers to read or modify arbitrary files via invalid characters between two . (dot) characters, which are filtered and result in a “..” sequence.
- CVE-2003-0282
- Directory traversal vulnerability allows attackers to overwrite arbitrary files via invalid characters between two . (dot) characters, which are filtered and result in a “..” sequence.
CWE-182 – Collapse of Data into Unsafe Value
Read Time:1 Minute, 16 Second
Description
The software filters data in a way that causes it to be reduced or “collapsed” into an unsafe value that violates an expected security property.
Modes of Introduction:
– Implementation
Related Weaknesses
Consequences
Access Control: Bypass Protection Mechanism
Potential Mitigations
Phase: Architecture and Design
Description:
Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
Phase: Implementation
Description:
Phase: Implementation
Description:
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 allowlist validation schemes by introducing dangerous inputs after they have been checked.
Phase:
Description:
Canonicalize the name to match that of the file system’s representation of the name. This can sometimes be achieved with an available API (e.g. in Win32 the GetFullPathName function).
CVE References
- CVE-2004-0815
- “/.////” in pathname collapses to absolute path.
- CVE-2005-3123
- “/.//..//////././” is collapsed into “/.././” after “..” and “//” sequences are removed.
- CVE-2002-0325
- “…/…//” collapsed to “…” due to removal of “./” in web server.
- CVE-2002-0784
- chain: HTTP server protects against “..” but allows “.” variants such as “////./../…/”. If the server removes “/..” sequences, the result would collapse into an unsafe value “////../” (CWE-182).
- CVE-2005-2169
- MFV. Regular expression intended to protect against directory traversal reduces “…/…//” to “../”.
- CVE-2001-1157
- XSS protection mechanism strips a
- XSS protection mechanism strips a
Read Time:45 Second
Description
The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are explicitly allowed by policy because the inputs are assumed to be safe, but the list is too permissive – that is, it allows an input that is unsafe, leading to resultant weaknesses.
Modes of Introduction:
– Implementation
Related Weaknesses
Consequences
Access Control: Bypass Protection Mechanism
Potential Mitigations
CVE References
- CVE-2019-12799
- chain: bypass of untrusted deserialization issue (CWE-502) by using an assumed-trusted class (CWE-183)
- CVE-2019-10458
- sandbox bypass using a method that is on an allowlist
- CVE-2017-1000095
- sandbox bypass using unsafe methods that are on an allowlist
- CVE-2019-10458
- CI/CD pipeline feature has unsafe elements in allowlist, allowing bypass of script restrictions
- CVE-2017-1000095
- Default allowlist includes unsafe methods, allowing bypass of sandbox
CWE-184 – Incomplete List of Disallowed Inputs
Read Time:2 Minute, 27 Second
Description
The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete, leading to resultant weaknesses.
Developers often try to protect their products against malicious input by performing tests against inputs that are known to be bad, such as special characters that can invoke new commands. However, such lists often only account for the most well-known bad inputs. Attackers may be able to find other malicious inputs that were not expected by the developer, allowing them to bypass the intended protection mechanism.
Modes of Introduction:
– Implementation
Related Weaknesses
CWE-693
CWE-1023
CWE-79
CWE-78
CWE-434
CWE-98
Consequences
Access Control: Bypass Protection Mechanism
Potential Mitigations
Phase: Implementation
Description:
Do not rely exclusively on detecting disallowed inputs. There are too many variants to encode a character, especially when different environments are used, so there is a high likelihood of missing some variants. Only use detection of disallowed inputs as a mechanism for detecting suspicious activity. Ensure that you are using other protection mechanisms that only identify “good” input – such as lists of allowed inputs – and ensure that you are properly encoding your outputs.
CVE References
- CVE-2008-2309
- product uses a denylist to identify potentially dangerous content, allowing attacker to bypass a warning
- CVE-2005-2782
- PHP remote file inclusion in web application that filters “http” and “https” URLs, but not “ftp”.
- CVE-2004-0542
- Programming language does not filter certain shell metacharacters in Windows environment.
- CVE-2004-0595
- XSS filter doesn’t filter null characters before looking for dangerous tags, which are ignored by web browsers. MIE and validate-before-cleanse.
- CVE-2005-3287
- Web-based mail product doesn’t restrict dangerous extensions such as ASPX on a web server, even though others are prohibited.
- CVE-2004-2351
- Resultant XSS when only
- Resultant XSS when only
Read Time:1 Minute, 49 Second
Description
The software specifies a regular expression in a way that causes data to be improperly matched or compared.
When the regular expression is used in protection mechanisms such as filtering or validation, this may allow an attacker to bypass the intended restrictions on the incoming data.
Modes of Introduction:
– Implementation
Related Weaknesses
Consequences
Other: Unexpected State, Varies by Context
When the regular expression is not correctly specified, data might have a different format or type than the rest of the program expects, producing resultant weaknesses or errors.
Access Control: Bypass Protection Mechanism
In PHP, regular expression checks can sometimes be bypassed with a null byte, leading to any number of weaknesses.
Potential Mitigations
Phase: Architecture and Design
Description:
Regular expressions can become error prone when defining a complex language even for those experienced in writing grammars. Determine if several smaller regular expressions simplify one large regular expression. Also, subject the regular expression to thorough testing techniques such as equivalence partitioning, boundary value analysis, and robustness. After testing and a reasonable confidence level is achieved, a regular expression may not be foolproof. If an exploit is allowed to slip through, then record the exploit and refactor the regular expression.
CVE References
- CVE-2002-2109
- Regexp isn’t “anchored” to the beginning or end, which allows spoofed values that have trusted values as substrings.
- CVE-2005-1949
- Regexp for IP address isn’t anchored at the end, allowing appending of shell metacharacters.
- CVE-2001-1072
- Bypass access restrictions via multiple leading slash, which causes a regular expression to fail.
- CVE-2000-0115
- Local user DoS via invalid regular expressions.
- CVE-2002-1527
- chain: Malformed input generates a regular expression error that leads to information exposure.
- CVE-2005-1061
- Certain strings are later used in a regexp, leading to a resultant crash.
- CVE-2005-2169
- MFV. Regular expression intended to protect against directory traversal reduces “…/…//” to “../”.
- CVE-2005-0603
- Malformed regexp syntax leads to information exposure in error message.
- CVE-2005-1820
- Code injection due to improper quoting of regular expression.
- CVE-2005-3153
- Null byte bypasses PHP regexp check.
- CVE-2005-4155
- Null byte bypasses PHP regexp check.