CWE-602
Client-Side Enforcement of Server-Side Security
MEDIUM
Draft
2007-05-07 00:00 +00:00
2023-06-29 00:00 +00:00
Alerte pour un CWE
Stay informed of any changes for a specific CWE.
Client-Side Enforcement of Server-Side Security
The product is composed of a server that relies on the client to implement a mechanism that is intended to protect the server.
Extended Description
When the server relies on protection mechanisms placed on the client side, an attacker can modify the client-side behavior to bypass the protection mechanisms, resulting in potentially unexpected interactions between the client and server. The consequences will vary, depending on what the mechanisms are trying to protect.
Informations
Modes Of Introduction
Architecture and Design : COMMISSION: This weakness refers to an incorrect design related to an architectural security tactic.Architecture and Design : Consider a product that consists of two or more processes or nodes that must interact closely, such as a client/server model. If the product uses protection schemes in the client in order to defend from attacks against the server, and the server does not use the same schemes, then an attacker could modify the client in a way that bypasses those schemes. This is a fundamental design flaw that is primary to many weaknesses.
Applicable Platforms
Language
Class: Not Language-Specific (Undetermined)Technologies
Class: ICS/OT (Undetermined)Class: Mobile (Undetermined)
Common Consequences
| Scope | Impact | Likelihood |
|---|---|---|
| Access Control Availability | Bypass Protection Mechanism, DoS: Crash, Exit, or Restart Note: Client-side validation checks can be easily bypassed, allowing malformed or unexpected input to pass into the application, potentially as trusted data. This may lead to unexpected states, behaviors and possibly a resulting crash. | |
| Access Control | Bypass Protection Mechanism, Gain Privileges or Assume Identity Note: Client-side checks for authentication can be easily bypassed, allowing clients to escalate their access levels and perform unintended actions. |
Observed Examples
| Reference | Description |
|---|---|
| SCADA system only uses client-side authentication, allowing adversaries to impersonate other users. | |
| ASP program allows upload of .asp files by bypassing client-side checks. | |
| steganography products embed password information in the carrier file, which can be extracted from a modified client. | |
| steganography products embed password information in the carrier file, which can be extracted from a modified client. | |
| client allows server to modify client's configuration and overwrite arbitrary files. |
Potential Mitigations
Phases : Architecture and DesignFor any security checks that are performed on the client side, ensure that these checks are duplicated on the server side. 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.
Even though client-side checks provide minimal benefits with respect to server-side security, they are still useful. First, they can support intrusion detection. If the server receives input that should have been rejected by the client, then it may be an indication of an attack. Second, client-side error-checking can provide helpful feedback to the user about the expectations for valid input. Third, there may be a reduction in server-side processing time for accidental input errors, although this is typically a small savings.
Phases : Architecture and Design
If some degree of trust is required between the two entities, then use integrity checking and strong authentication to ensure that the inputs are coming from a trusted source. Design the product so that this trust is managed in a centralized fashion, especially if there are complex or numerous communication channels, in order to reduce the risks that the implementer will mistakenly omit a check in a single code path.
Phases : Testing
Use dynamic tools and techniques that interact with the software using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
Phases : Testing
Use tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session. These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.
Vulnerability Mapping Notes
Rationale : This CWE entry is a Class and might have Base-level children that would be more appropriateComments : Examine children of this entry to see if there is a better fit
Related Attack Patterns
| CAPEC-ID | Attack Pattern Name |
|---|---|
| CAPEC-162 | Manipulating Hidden Fields An adversary exploits a weakness in the server's trust of client-side processing by modifying data on the client-side, such as price information, and then submitting this data to the server, which processes the modified data. For example, eShoplifting is a data manipulation attack against an on-line merchant during a purchasing transaction. The manipulation of price, discount or quantity fields in the transaction message allows the adversary to acquire items at a lower cost than the merchant intended. The adversary performs a normal purchasing transaction but edits hidden fields within the HTML form response that store price or other information to give themselves a better deal. The merchant then uses the modified pricing information in calculating the cost of the selected items. |
| CAPEC-202 | Create Malicious Client An adversary creates a client application to interface with a target service where the client violates assumptions the service makes about clients. Services that have designated client applications (as opposed to services that use general client applications, such as IMAP or POP mail servers which can interact with any IMAP or POP client) may assume that the client will follow specific procedures. |
| CAPEC-207 | Removing Important Client Functionality An adversary removes or disables functionality on the client that the server assumes to be present and trustworthy. |
| CAPEC-208 | Removing/short-circuiting 'Purse' logic: removing/mutating 'cash' decrements An attacker removes or modifies the logic on a client associated with monetary calculations resulting in incorrect information being sent to the server. A server may rely on a client to correctly compute monetary information. For example, a server might supply a price for an item and then rely on the client to correctly compute the total cost of a purchase given the number of items the user is buying. If the attacker can remove or modify the logic that controls these calculations, they can return incorrect values to the server. The attacker can use this to make purchases for a fraction of the legitimate cost or otherwise avoid correct billing for activities. |
| CAPEC-21 | Exploitation of Trusted Identifiers An adversary guesses, obtains, or "rides" a trusted identifier (e.g. session ID, resource ID, cookie, etc.) to perform authorized actions under the guise of an authenticated user or service. |
| CAPEC-31 | Accessing/Intercepting/Modifying HTTP Cookies This attack relies on the use of HTTP Cookies to store credentials, state information and other critical data on client systems. There are several different forms of this attack. The first form of this attack involves accessing HTTP Cookies to mine for potentially sensitive data contained therein. The second form involves intercepting this data as it is transmitted from client to server. This intercepted information is then used by the adversary to impersonate the remote user/session. The third form is when the cookie's content is modified by the adversary before it is sent back to the server. Here the adversary seeks to convince the target server to operate on this falsified information. |
| CAPEC-383 | Harvesting Information via API Event Monitoring An adversary hosts an event within an application framework and then monitors the data exchanged during the course of the event for the purpose of harvesting any important data leaked during the transactions. One example could be harvesting lists of usernames or userIDs for the purpose of sending spam messages to those users. One example of this type of attack involves the adversary creating an event within the sub-application. Assume the adversary hosts a "virtual sale" of rare items. As other users enter the event, the attacker records via AiTM (CAPEC-94) proxy the user_ids and usernames of everyone who attends. The adversary would then be able to spam those users within the application using an automated script. |
| CAPEC-384 | Application API Message Manipulation via Man-in-the-Middle An attacker manipulates either egress or ingress data from a client within an application framework in order to change the content of messages. Performing this attack can allow the attacker to gain unauthorized privileges within the application, or conduct attacks such as phishing, deceptive strategies to spread malware, or traditional web-application attacks. The techniques require use of specialized software that allow the attacker to perform adversary-in-the-middle (CAPEC-94) communications between the web browser and the remote system. Despite the use of AiTH software, the attack is actually directed at the server, as the client is one node in a series of content brokers that pass information along to the application framework. Additionally, it is not true "Adversary-in-the-Middle" attack at the network layer, but an application-layer attack the root cause of which is the master applications trust in the integrity of code supplied by the client. |
| CAPEC-385 | Transaction or Event Tampering via Application API Manipulation An attacker hosts or joins an event or transaction within an application framework in order to change the content of messages or items that are being exchanged. Performing this attack allows the attacker to manipulate content in such a way as to produce messages or content that look authentic but may contain deceptive links, substitute one item or another, spoof an existing item and conduct a false exchange, or otherwise change the amounts or identity of what is being exchanged. The techniques require use of specialized software that allow the attacker to man-in-the-middle communications between the web browser and the remote system in order to change the content of various application elements. Often, items exchanged in game can be monetized via sales for coin, virtual dollars, etc. The purpose of the attack is for the attack to scam the victim by trapping the data packets involved the exchange and altering the integrity of the transfer process. |
| CAPEC-386 | Application API Navigation Remapping An attacker manipulates either egress or ingress data from a client within an application framework in order to change the destination and/or content of links/buttons displayed to a user within API messages. Performing this attack allows the attacker to manipulate content in such a way as to produce messages or content that looks authentic but contains links/buttons that point to an attacker controlled destination. Some applications make navigation remapping more difficult to detect because the actual HREF values of images, profile elements, and links/buttons are masked. One example would be to place an image in a user's photo gallery that when clicked upon redirected the user to an off-site location. Also, traditional web vulnerabilities (such as CSRF) can be constructed with remapped buttons or links. In some cases navigation remapping can be used for Phishing attacks or even means to artificially boost the page view, user site reputation, or click-fraud. |
| CAPEC-387 | Navigation Remapping To Propagate Malicious Content An adversary manipulates either egress or ingress data from a client within an application framework in order to change the content of messages and thereby circumvent the expected application logic. |
| CAPEC-388 | Application API Button Hijacking An attacker manipulates either egress or ingress data from a client within an application framework in order to change the destination and/or content of buttons displayed to a user within API messages. Performing this attack allows the attacker to manipulate content in such a way as to produce messages or content that looks authentic but contains buttons that point to an attacker controlled destination. |
References
REF-7
Writing Secure CodeMichael Howard, David LeBlanc.
https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223
REF-1283
OT:ICEFALL: The legacy of "insecure by design" and its implications for certifications and risk managementForescout Vedere Labs.
https://www.forescout.com/resources/ot-icefall-report/
Submission
| Name | Organization | Date | Date Release | Version |
|---|---|---|---|---|
| CWE Community | Draft 6 |
Modifications
| Name | Organization | Date | Comment |
|---|---|---|---|
| Eric Dalci | Cigital | updated Time_of_Introduction | |
| CWE Content Team | MITRE | updated Relationships, Other_Notes, Taxonomy_Mappings, Weakness_Ordinalities | |
| CWE Content Team | MITRE | updated Demonstrative_Examples, Description, Likelihood_of_Exploit, Name, Observed_Examples, Other_Notes, Potential_Mitigations, Relationships, Research_Gaps, Time_of_Introduction | |
| CWE Content Team | MITRE | updated Potential_Mitigations | |
| CWE Content Team | MITRE | updated Demonstrative_Examples | |
| CWE Content Team | MITRE | updated Related_Attack_Patterns, Relationships | |
| CWE Content Team | MITRE | updated Applicable_Platforms, Common_Consequences, Description | |
| CWE Content Team | MITRE | updated References | |
| CWE Content Team | MITRE | updated Related_Attack_Patterns | |
| CWE Content Team | MITRE | updated Related_Attack_Patterns | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated Common_Consequences | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated Related_Attack_Patterns | |
| CWE Content Team | MITRE | updated Applicable_Platforms, Enabling_Factors_for_Exploitation, Modes_of_Introduction, References, Relationships | |
| CWE Content Team | MITRE | updated References | |
| CWE Content Team | MITRE | updated Related_Attack_Patterns | |
| CWE Content Team | MITRE | updated Applicable_Platforms, Relationships | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated Research_Gaps | |
| CWE Content Team | MITRE | updated Demonstrative_Examples, Description, Observed_Examples, References, Relationships | |
| CWE Content Team | MITRE | updated Applicable_Platforms, Relationships, Type | |
| CWE Content Team | MITRE | updated Relationships | |
| CWE Content Team | MITRE | updated Mapping_Notes |
2024©
tesweb SA
