CVE-2021-41269 (published 2021-11-15T21:15Z)

cron-utils is a Java library to define, parse, validate, migrate crons as well as get human readable descriptions for them. In affected versions A template Injection was identified in cron-utils enabling attackers to inject arbitrary Java EL expressions, leading to unauthenticated Remote Code Execution (RCE) vulnerability. Versions up to 9.1.2 are susceptible to this vulnerability. Please note, that only projects using the @Cron annotation to validate untrusted Cron expressions are affected. The issue was patched and a new version was released. Please upgrade to version 9.1.6. There are no known workarounds known.

Severity: MEDIUM
CVSS v2 base score: 6.8 (AV:N/AC:M/Au:N/C:P/I:P/A:P)
CVSS v3 base score: 9.8, CRITICAL (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-94
cwe_name: Improper Control of Generation of Code ('Code Injection')
description: The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
extended_description: 
            When a product allows a user's input to contain code syntax, it might be possible for an attacker to craft the code in such a way that it will alter the intended control flow of the product. Such an alteration could lead to arbitrary code execution.
            Injection problems encompass a wide variety of issues -- all mitigated in very different ways. For this reason, the most effective way to discuss these weaknesses is to note the distinct features which classify them as injection weaknesses. The most important issue to note is that all injection problems share one thing in common -- i.e., they allow for the injection of control plane data into the user-controlled data plane. This means that the execution of the process may be altered by sending code in through legitimate data channels, using no other mechanism. While buffer overflows, and many other flaws, involve the use of some further issue to gain execution, injection problems need only for the data to be parsed. The most classic instantiations of this category of weakness are SQL injection and format string vulnerabilities.
         
         

Fix information:
repo_url: https://github.com/jmrozanec/cron-utils
commit_details: repo_url: https://github.com/jmrozanec/cron-utils
author: jmrozanec
author_date: 2021-10-30 15:11:58+02:00
msg: Merge pull request #493 from pwntester/patch-1

Prevent arbitrary EL expression evaluation
repository: repo_url: https://github.com/jmrozanec/cron-utils
repo_name: jmrozanec/cron-utils
description: Cron utils for parsing, validations and human readable descriptions as well as date/time interoperability.
repo_language: Java
owner: jmrozanec
repo_url: https://github.com/jmrozanec/cron-utils
commit_details: repo_url: https://github.com/jmrozanec/cron-utils
author: jmrozanec
author_date: 2021-10-30 15:12:11+02:00
msg: Merge pull request #494 from NielsDoucet/RCE-fix

Resolve RCE vulnerability.
repository: repo_url: https://github.com/jmrozanec/cron-utils
repo_name: jmrozanec/cron-utils
description: Cron utils for parsing, validations and human readable descriptions as well as date/time interoperability.
repo_language: Java
owner: jmrozanec