CVE-2021-21249 Vulnerability Details

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CVE-2021-21249 Metadata Quick Info

CVE Published: 15/01/2021 | CVE Updated: 03/08/2024 | CVE Year: 2021
Source: GitHub_M | Vendor: theonedev | Product: onedev
Status : PUBLISHED

CVE-2021-21249 Description

OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, there is an issue involving YAML parsing which can lead to post-auth remote code execution. In order to parse and process YAML files, OneDev uses SnakeYaml which by default (when not using `SafeConstructor`) allows the instantiation of arbitrary classes. We can leverage that to run arbitrary code by instantiating classes such as `javax.script.ScriptEngineManager` and using `URLClassLoader` to load the script engine provider, resulting in the instantiation of a user controlled class. For a full example refer to the referenced GHSA. This issue was addressed in 4.0.3 by only allowing certain known classes to be deserialized

Metrics

CVSS Version: 3.1 | Base Score: 9.6 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

l➤ Exploitability Metrics:
    Attack Vector (AV)* NETWORK
    Attack Complexity (AC)* LOW
    Privileges Required (PR)* LOW
    User Interaction (UI)* NONE
    Scope (S)* CHANGED

l➤ Impact Metrics:
    Confidentiality Impact (C)* HIGH
    Integrity Impact (I)* HIGH
    Availability Impact (A)* NONE

Weakness Enumeration (CWE)

CWE-ID: CWE-74
CWE Name: CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ( Injection )
Source: theonedev

Common Attack Pattern Enumeration and Classification (CAPEC)

CAPEC-ID:
CAPEC Description:


Source: NVD (National Vulnerability Database).