All posts by rocco

CWE

CWE-236 – Improper Handling of Undefined Parameters

Read Time:24 Second

Description

The software does not handle or incorrectly handles when a particular parameter, field, or argument name is not defined or supported by the product.

Modes of Introduction:

– Architecture and Design

 

 

Related Weaknesses

CWE-233

 

Consequences

Integrity: Unexpected State

 

Potential Mitigations

CVE References

  • CVE-2002-1488
    • Crash in IRC client via PART message from a channel the user is not in.
  • CVE-2001-0650
    • Router crash or bad route modification using BGP updates with invalid transitive attribute.
CWE

CWE-200 – Exposure of Sensitive Information to an Unauthorized Actor

Read Time:1 Minute, 47 Second

Description

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

Modes of Introduction:

– Architecture and Design

 

Likelihood of Exploit: High

 

Related Weaknesses

CWE-668

 

Consequences

Confidentiality: Read Application Data

 

Potential Mitigations

Phase: Architecture and Design

Description: 

CVE References

  • CVE-2001-1483
    • Enumeration of valid usernames based on inconsistent responses
  • CVE-2001-1528
    • Account number enumeration via inconsistent responses.
  • CVE-2004-2150
    • User enumeration via discrepancies in error messages.
  • CVE-2005-1205
    • Telnet protocol allows servers to obtain sensitive environment information from clients.
  • CVE-2002-1725
    • Script calls phpinfo(), revealing system configuration to web user
  • CVE-2002-0515
    • Product sets a different TTL when a port is being filtered than when it is not being filtered, which allows remote attackers to identify filtered ports by comparing TTLs.
  • CVE-2004-0778
    • Version control system allows remote attackers to determine the existence of arbitrary files and directories via the -X command for an alternate history file, which causes different error messages to be returned.
  • CVE-2000-1117
    • Virtual machine allows malicious web site operators to determine the existence of files on the client by measuring delays in the execution of the getSystemResource method.
  • CVE-2003-0190
    • Product immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack.
  • CVE-2008-2049
    • POP3 server reveals a password in an error message after multiple APOP commands are sent. Might be resultant from another weakness.
  • CVE-2007-5172
    • Program reveals password in error message if attacker can trigger certain database errors.
  • CVE-2008-4638
    • Composite: application running with high privileges (CWE-250) allows user to specify a restricted file to process, which generates a parsing error that leaks the contents of the file (CWE-209).
  • CVE-2007-1409
    • Direct request to library file in web application triggers pathname leak in error message.
  • CVE-2005-0603
    • Malformed regexp syntax leads to information exposure in error message.
  • CVE-2003-1078
    • FTP client with debug option enabled shows password to the screen.
CWE

CWE-201 – Insertion of Sensitive Information Into Sent Data

Read Time:1 Minute, 1 Second

Description

The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.

Sensitive information could include data that is sensitive in and of itself (such as credentials or private messages), or otherwise useful in the further exploitation of the system (such as internal file system structure).

Modes of Introduction:

– Implementation

 

 

Related Weaknesses

CWE-200
CWE-209
CWE-202

 

Consequences

Confidentiality: Read Files or Directories, Read Memory, Read Application Data

Sensitive data may be exposed to attackers.

 

Potential Mitigations

Phase: Requirements

Description: 

Specify which data in the software should be regarded as sensitive. Consider which types of users should have access to which types of data.

Phase: Implementation

Description: 

Ensure that any possibly sensitive data specified in the requirements is verified with designers to ensure that it is either a calculated risk or mitigated elsewhere. Any information that is not necessary to the functionality should be removed in order to lower both the overhead and the possibility of security sensitive data being sent.

Phase: System Configuration

Description: 

Setup default error messages so that unexpected errors do not disclose sensitive information.

Phase: Architecture and Design

Description: 

CVE References

CWE

CWE-202 – Exposure of Sensitive Information Through Data Queries

Read Time:41 Second

Description

When trying to keep information confidential, an attacker can often infer some of the information by using statistics.

In situations where data should not be tied to individual users, but a large number of users should be able to make queries that “scrub” the identity of users, it may be possible to get information about a user — e.g., by specifying search terms that are known to be unique to that user.

Modes of Introduction:

– Architecture and Design

 

Likelihood of Exploit: Medium

 

Related Weaknesses

CWE-1230

 

Consequences

Confidentiality: Read Files or Directories, Read Application Data

Sensitive information may possibly be leaked through data queries accidentally.

 

Potential Mitigations

Phase: Architecture and Design

Description: 

This is a complex topic. See the book Translucent Databases for a good discussion of best practices.

CVE References

CWE

CWE-203 – Observable Discrepancy

Read Time:3 Minute, 36 Second

Description

The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not.

Discrepancies can take many forms, and variations may be detectable in timing, control flow, communications such as replies or requests, or general behavior. These discrepancies can reveal information about the product’s operation or internal state to an unauthorized actor. In some cases, discrepancies can be used by attackers to form a side channel.

Modes of Introduction:

– Architecture and Design

 

 

Related Weaknesses

CWE-200
CWE-200

 

Consequences

Confidentiality, Access Control: Read Application Data, Bypass Protection Mechanism

An attacker can gain access to sensitive information about the system, including authentication information that may allow an attacker to gain access to the system.

Confidentiality: Read Application Data

When cryptographic primitives are vulnerable to side-channel-attacks, this could be used to reveal unencrypted plaintext in the worst case.

 

Potential Mitigations

Phase: Architecture and Design

Description: 

Phase: Implementation

Description: 

CVE References

  • CVE-2020-8695
    • Observable discrepancy in the RAPL interface for some Intel processors allows information disclosure.
  • CVE-2002-2094
    • This, and others, use “..” attacks and monitor error responses, so there is overlap with directory traversal.
  • CVE-2001-1483
    • Enumeration of valid usernames based on inconsistent responses
  • CVE-2001-1528
    • Account number enumeration via inconsistent responses.
  • CVE-2004-2150
    • User enumeration via discrepancies in error messages.
  • CVE-2005-1650
    • User enumeration via discrepancies in error messages.
  • CVE-2004-0294
    • Bulletin Board displays different error messages when a user exists or not, which makes it easier for remote attackers to identify valid users and conduct a brute force password guessing attack.
  • CVE-2004-0243
    • Operating System, when direct remote login is disabled, displays a different message if the password is correct, which allows remote attackers to guess the password via brute force methods.
  • CVE-2002-0514
    • Product allows remote attackers to determine if a port is being filtered because the response packet TTL is different than the default TTL.
  • CVE-2002-0515
    • Product sets a different TTL when a port is being filtered than when it is not being filtered, which allows remote attackers to identify filtered ports by comparing TTLs.
  • CVE-2002-0208
    • Product modifies TCP/IP stack and ICMP error messages in unusual ways that show the product is in use.
  • CVE-2004-2252
    • Behavioral infoleak by responding to SYN-FIN packets.
  • CVE-2001-1387
    • Product may generate different responses than specified by the administrator, possibly leading to an information leak.
  • CVE-2004-0778
    • Version control system allows remote attackers to determine the existence of arbitrary files and directories via the -X command for an alternate history file, which causes different error messages to be returned.
  • CVE-2004-1428
    • FTP server generates an error message if the user name does not exist instead of prompting for a password, which allows remote attackers to determine valid usernames.
  • CVE-2003-0078
    • SSL implementation does not perform a MAC computation if an incorrect block cipher padding is used, which causes an information leak (timing discrepancy) that may make it easier to launch cryptographic attacks that rely on distinguishing between padding and MAC verification errors, possibly leading to extraction of the original plaintext, aka the “Vaudenay timing attack.”
  • CVE-2000-1117
    • Virtual machine allows malicious web site operators to determine the existence of files on the client by measuring delays in the execution of the getSystemResource method.
  • CVE-2003-0637
    • Product uses a shorter timeout for a non-existent user than a valid user, which makes it easier for remote attackers to guess usernames and conduct brute force password guessing.
  • CVE-2003-0190
    • Product immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack.
  • CVE-2004-1602
    • FTP server responds in a different amount of time when a given username exists, which allows remote attackers to identify valid usernames by timing the server response.
  • CVE-2005-0918
    • Browser allows remote attackers to determine the existence of arbitrary files by setting the src property to the target filename and using Javascript to determine if the web page immediately stops loading, which indicates whether the file exists or not.
CWE

CWE-204 – Observable Response Discrepancy

Read Time:1 Minute, 49 Second

Description

The product provides different responses to incoming requests in a way that reveals internal state information to an unauthorized actor outside of the intended control sphere.

This issue frequently occurs during authentication, where a difference in failed-login messages could allow an attacker to determine if the username is valid or not. These exposures can be inadvertent (bug) or intentional (design).

Modes of Introduction:

– Architecture and Design

 

 

Related Weaknesses

CWE-203

 

Consequences

Confidentiality, Access Control: Read Application Data, Bypass Protection Mechanism

 

Potential Mitigations

Phase: Architecture and Design

Description: 

Phase: Implementation

Description: 

CVE References

  • CVE-2002-2094
    • This, and others, use “..” attacks and monitor error responses, so there is overlap with directory traversal.
  • CVE-2001-1483
    • Enumeration of valid usernames based on inconsistent responses
  • CVE-2001-1528
    • Account number enumeration via inconsistent responses.
  • CVE-2004-2150
    • User enumeration via discrepancies in error messages.
  • CVE-2005-1650
    • User enumeration via discrepancies in error messages.
  • CVE-2004-0294
    • Bulletin Board displays different error messages when a user exists or not, which makes it easier for remote attackers to identify valid users and conduct a brute force password guessing attack.
  • CVE-2004-0243
    • Operating System, when direct remote login is disabled, displays a different message if the password is correct, which allows remote attackers to guess the password via brute force methods.
  • CVE-2002-0514
    • Product allows remote attackers to determine if a port is being filtered because the response packet TTL is different than the default TTL.
  • CVE-2002-0515
    • Product sets a different TTL when a port is being filtered than when it is not being filtered, which allows remote attackers to identify filtered ports by comparing TTLs.
  • CVE-2001-1387
    • Product may generate different responses than specified by the administrator, possibly leading to an information leak.
  • CVE-2004-0778
    • Version control system allows remote attackers to determine the existence of arbitrary files and directories via the -X command for an alternate history file, which causes different error messages to be returned.
  • CVE-2004-1428
    • FTP server generates an error message if the user name does not exist instead of prompting for a password, which allows remote attackers to determine valid usernames.
CWE

CWE-205 – Observable Behavioral Discrepancy

Read Time:42 Second

Description

The product’s behaviors indicate important differences that may be observed by unauthorized actors in a way that reveals (1) its internal state or decision process, or (2) differences from other products with equivalent functionality.

Ideally, a product should provide as little information about its internal operations as possible. Otherwise, attackers could use knowledge of these internal operations to simplify or optimize their attack. In some cases, behavioral discrepancies can be used by attackers to form a side channel.

Modes of Introduction:

– Architecture and Design

 

 

Related Weaknesses

CWE-203
CWE-514

 

Consequences

Confidentiality, Access Control: Read Application Data, Bypass Protection Mechanism

 

Potential Mitigations

CVE References

  • CVE-2002-0208
    • Product modifies TCP/IP stack and ICMP error messages in unusual ways that show the product is in use.
  • CVE-2004-2252
    • Behavioral infoleak by responding to SYN-FIN packets.
CWE

CWE-206 – Observable Internal Behavioral Discrepancy

Read Time:1 Minute, 33 Second

Description

The product performs multiple behaviors that are combined to produce a single result, but the individual behaviors are observable separately in a way that allows attackers to reveal internal state or internal decision points.

Ideally, a product should provide as little information as possible to an attacker. Any hints that the attacker may be making progress can then be used to simplify or optimize the attack. For example, in a login procedure that requires a username and password, ultimately there is only one decision: success or failure. However, internally, two separate actions are performed: determining if the username exists, and checking if the password is correct. If the product behaves differently based on whether the username exists or not, then the attacker only needs to concentrate on the password.

Modes of Introduction:

– Architecture and Design

 

 

Related Weaknesses

CWE-205

 

Consequences

Confidentiality, Access Control: Read Application Data, Bypass Protection Mechanism

 

Potential Mitigations

Phase:

Description: 

Setup generic response pages for error conditions. The error page should not disclose information about the success or failure of a sensitive operation. For instance, the login page should not confirm that the login is correct and the password incorrect. The attacker who tries random account name may be able to guess some of them. Confirming that the account exists would make the login page more susceptible to brute force attack.

CVE References

  • CVE-2002-2031
    • File existence via infoleak monitoring whether “onerror” handler fires or not.
  • CVE-2005-2025
    • Valid groupname enumeration via behavioral infoleak (sends response if valid, doesn’t respond if not).
  • CVE-2001-1497
    • Behavioral infoleak in GUI allows attackers to distinguish between alphanumeric and non-alphanumeric characters in a password, thus reducing the search space.
  • CVE-2003-0190
    • Product immediately sends an error message when user does not exist instead of waiting until the password is provided, allowing username enumeration.