A permissive list of allowed inputs vulnerability [CWE-183] in FortiGate version 7.2.3 and below, version 7.0.9 and below Policy-based NGFW…
A permissive list of allowed inputs vulnerability [CWE-183] in FortiGate version 7.2.3 and below, version 7.0.9 and below Policy-based NGFW Mode may allow an authenticated SSL-VPN user to bypass the policy via bookmarks in the web portal.
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.
https://cwe.mitre.org/data/definitions/183.html →Open in CWE collection →Some APIs will strip certain leading characters from a string of parameters. An adversary can intentionally introduce leading "ghost" characters (extra characters that don't affect the validity of the request at the API layer) that enable the input to pass the filters and therefore process the adversary's input. This occurs when the targeted API will accept input data in several syntactic forms and interpret it in the equivalent semantic way, while the filter does not take into account the full spectrum of the syntactic forms acceptable to the targeted API.
https://capec.mitre.org/data/definitions/3.html →Open in CAPEC collection →An attacker supplies the target software with input data that contains sequences of special characters designed to bypass input validation logic. This exploit relies on the target making multiples passes over the input data and processing a "layer" of special characters with each pass. In this manner, the attacker can disguise input that would otherwise be rejected as invalid by concealing it with layers of special/escape characters that are stripped off by subsequent processing steps. The goal is to first discover cases where the input validation layer executes before one or more parsing layers. That is, user input may go through the following logic in an application: <parser1> --> <input validator> --> <parser2>. In such cases, the attacker will need to provide input that will pass through the input validator, but after passing through parser2, will be converted into something that the input validator was supposed to stop.
https://capec.mitre.org/data/definitions/43.html →Open in CAPEC collection →An attacker may provide a Unicode string to a system component that is not Unicode aware and use that to circumvent the filter or cause the classifying mechanism to fail to properly understanding the request. That may allow the attacker to slip malicious data past the content filter and/or possibly cause the application to route the request incorrectly.
https://capec.mitre.org/data/definitions/71.html →Open in CAPEC collection →The adversary utilizes a repeating of the encoding process for a set of characters (that is, character encoding a character encoding of a character) to obfuscate the payload of a particular request. This may allow the adversary to bypass filters that attempt to detect illegal characters or strings, such as those that might be used in traversal or injection attacks. Filters may be able to catch illegal encoded strings, but may not catch doubly encoded strings. For example, a dot (.), often used in path traversal attacks and therefore often blocked by filters, could be URL encoded as %2E. However, many filters recognize this encoding and would still block the request. In a double encoding, the % in the above URL encoding would be encoded again as %25, resulting in %252E which some filters might not catch, but which could still be interpreted as a dot (.) by interpreters on the target.
https://capec.mitre.org/data/definitions/120.html →Open in CAPEC collection →| Product | Vendor | Status |
|---|---|---|
| fortios | * | Tracked |