Vulnerabilities > CVE-2022-1525 - Client-Side Enforcement of Server-Side Security vulnerability in Cognex 3D-A1000 Dimensioning System Firmware 1.0.3(3354)

An adversary is able to exploit features of the target that should be reserved for privileged users or administrators but are exposed to use by lower or non-privileged accounts. Access to sensitive information and functionality must be controlled to ensure that only authorized users are able to access these resources. If access control mechanisms are absent or misconfigured, a user may be able to access resources that are intended only for higher level users. An adversary may be able to exploit this to utilize a less trusted account to gain information and perform activities reserved for more trusted accounts. This attack differs from privilege escalation and other privilege stealing attacks in that the adversary never actually escalates their privileges but instead is able to use a lesser degree of privilege to access resources that should be (but are not) reserved for higher privilege accounts. Likewise, the adversary does not exploit trust or subvert systems - all control functionality is working as configured but the configuration does not adequately protect sensitive resources at an appropriate level.

An attacker 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 to effect a change in the state of an ordinary transaction. 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 attacker to acquire items at a lower cost than the merchant intended. The attacker 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.

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. For example, servers may assume that clients will accurately compute values (such as prices), will send correctly structured messages, and will attempt to ensure efficient interactions with the server. By reverse-engineering a client and creating their own version, an adversary can take advantage of these assumptions to abuse service functionality. For example, a purchasing service might send a unit price to its client and expect the client to correctly compute the total cost of a purchase. If the adversary uses a malicious client, however, the adversary could ignore the server input and declare any total price. Likewise, an adversary could configure the client to retain network or other server resources for longer than legitimately necessary in order to degrade server performance. Even services with general clients can be susceptible to this attack if they assume certain client behaviors. However, such services generally can make fewer assumptions about the behavior of their clients in the first place and, as such, are less likely to make assumptions that an adversary can exploit.

An attacker removes or disables functionality on the client that the server assumes to be present and trustworthy. Client applications may include functionality that a server relies on for correct and secure operation. This functionality can include, but is not limited to, filters to prevent the sending of dangerous content to the server, logical functionality such as price calculations, and authentication logic to ensure that only authorized users are utilizing the client. If an attacker can disable this functionality on the client, they can perform actions that the server believes are prohibited. This can result in client behavior that violates assumptions by the server leading to a variety of possible attacks. In the above examples, this could include the sending of dangerous content (such as scripts) to the server, incorrect price calculations, or unauthorized access to server resources.

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.