COMMON WEAKNESS ENUMERATIONIncomplete

CWE-643

Improper Neutralization of Data within XPath Expressions ('XPath Injection')

The product uses external input to dynamically construct an XPath expression used to retrieve data from an XML database, but it does not neutralize or incorrectly neutralizes that input. This allows an attacker to control the structure of the query.

Soyutlama

Base

Yapı

Simple

Sömürü İhtimali

High

Problemi anla

Problem nedir?

The product uses external input to dynamically construct an XPath expression used to retrieve data from an XML database, but it does not neutralize or incorrectly neutralizes that input. This allows an attacker to control the structure of the query.

Genişletilmiş açıklama

The net effect is that the attacker will have control over the information selected from the XML database and may use that ability to control application flow, modify logic, retrieve unauthorized data, or bypass important checks (e.g. authentication).

Kök neden

Problem nasıl ve ne zaman oluşur?

Yaşam döngüsü evresi

Implementation

REALIZATION: This weakness is caused during implementation of an architectural security tactic.

Risk

Başarılı sömürü neye yol açar?

Bypass Protection Mechanism

Etkilenen güvenlik alanları: Access Control

Controlling application flow (e.g. bypassing authentication).
Read Application Data

Etkilenen güvenlik alanları: Confidentiality

The attacker could read restricted XML content.

Savunma

Nasıl önlenir ve çözülür?

Implementation

Uygulama aşaması savunması

Detay
Use parameterized XPath queries (e.g. using XQuery). This will help ensure separation between data plane and control plane.

Implementation

Uygulama aşaması savunması

Detay
Properly validate user input. Reject data where appropriate, filter where appropriate and escape where appropriate. Make sure input that will be used in XPath queries is safe in that context.

Doğrulama

Nasıl tespit edilir?

Automated Static Analysis

High
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.)