10 CVE-2026-3490
picklescan before 1.0.4 fails to block pkgutil.resolve_name, allowing attackers to bypass the entire blocklist by resolving any dangerous function through indirect REDUCE calls. Remote attackers can invoke any blocked function such as os.system, builtins.exec, or subprocess.call to achieve remote code execution.
https://nvd.nist.gov/vuln/detail/CVE-2026-3490
Categories
CWE-183 : Permissive List of Allowed Inputs
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. This is used by CWE and CAPEC instead of other commonly-used terms. Its counterpart is denylist. This is often used by security tools such as firewalls, email or web gateways, proxies, etc. This term is frequently used, but usage has been declining as organizations have started to adopt other terms. Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.) chain: bypass of untrusted deserialization issue (CWE-502) by using an assumed-trusted class (CWE-183) sandbox bypass using a method that is on an allowlist sandbox bypass using unsafe methods that are on an allowlist CI/CD pipeline feature has unsafe elements in allowlist, allowing bypass of script restrictions Default allowlist includes unsafe methods, allowing bypass of sandbox
References
AFFECTED (from MITRE)
| Vendor |
Product |
Versions |
| picklescan |
picklescan |
- < 1.0.4 [affected]
- 1.0.4 [unaffected]
|
| © 2022 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. |
CPE
| cpe |
start |
end |
| Configuration 1 |
| cpe:2.3:a:mmaitre314:picklescan:*:*:*:*:*:*:*:* |
|
< 1.0.4 |
REMEDIATION
EXPLOITS
Exploit-db.com
| id |
description |
date |
|
| No known exploits |
POC Github
Other Nist (github, ...)
CAPEC
Common Attack Pattern Enumerations and Classifications
| id |
description |
severity |
| 120 |
Double Encoding
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. [Survey the application for user-controllable inputs] Using a browser, an automated tool or by inspecting the application, an attacker records all entry points to the application. [Probe entry points to locate vulnerabilities] Try double-encoding for parts of the input in order to try to get past the filters. For instance, by double encoding certain characters in the URL (e.g. dots and slashes) an adversary may try to get access to restricted resources on the web server or force browse to protected pages (thus subverting the authorization service). An adversary can also attempt other injection style attacks using this attack pattern: command injection, SQL injection, etc. |
Medium |
| 3 |
Using Leading 'Ghost' Character Sequences to Bypass Input Filters
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. [Survey the application for user-controllable inputs] Using a browser, an automated tool or by inspecting the application, an adversary records all entry points to the application. [Probe entry points to locate vulnerabilities] The adversary uses the entry points gathered in the "Explore" phase as a target list and injects various leading 'Ghost' character sequences to determine how to application filters them. [Bypass input filtering] Using what the adversary learned about how the application filters input data, they craft specific input data that bypasses the filter. This can lead to directory traversal attacks, arbitrary shell command execution, corruption of files, etc. |
Medium |
| 43 |
Exploiting Multiple Input Interpretation Layers
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. [Determine application/system inputs where bypassing input validation is desired] The attacker first needs to determine all of the application's/system's inputs where input validation is being performed and where they want to bypass it. [Determine which character encodings are accepted by the application/system] The attacker then needs to provide various character encodings to the application/system and determine which ones are accepted. The attacker will need to observe the application's/system's response to the encoded data to determine whether the data was interpreted properly. [Combine multiple encodings accepted by the application.] The attacker now combines encodings accepted by the application. The attacker may combine different encodings or apply the same encoding multiple times. [Leverage ability to bypass input validation] Attacker leverages their ability to bypass input validation to gain unauthorized access to system. There are many attacks possible, and a few examples are mentioned here. |
High |
| 71 |
Using Unicode Encoding to Bypass Validation Logic
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. [Survey the application for user-controllable inputs] Using a browser or an automated tool, an attacker follows all public links and actions on a web site. They record all the links, the forms, the resources accessed and all other potential entry-points for the web application. [Probe entry points to locate vulnerabilities] The attacker uses the entry points gathered in the "Explore" phase as a target list and injects various Unicode encoded payloads to determine if an entry point actually represents a vulnerability with insufficient validation logic and to characterize the extent to which the vulnerability can be exploited. |
High |
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