COMMON WEAKNESS ENUMERATIONDraft

CWE-378

Creation of Temporary File With Insecure Permissions

Opening temporary files without appropriate measures or controls can leave the file, its contents and any function that it impacts vulnerable to attack.

Soyutlama

Base

Yapı

Simple

Sömürü İhtimali

High

Problemi anla

Problem nedir?

Opening temporary files without appropriate measures or controls can leave the file, its contents and any function that it impacts vulnerable to attack.

Kök neden

Problem nasıl ve ne zaman oluşur?

Yaşam döngüsü evresi

Implementation

Risk

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Read Application Data

Etkilenen güvenlik alanları: Confidentiality

If the temporary file can be read by the attacker, sensitive information may be in that file which could be revealed.
Other

Etkilenen güvenlik alanları: Authorization, Other

If that file can be written to by the attacker, the file might be moved into a place to which the attacker does not have access. This will allow the attacker to gain selective resource access-control privileges.
Other

Etkilenen güvenlik alanları: Integrity, Other

Depending on the data stored in the temporary file, there is the potential for an attacker to gain an additional input vector which is trusted as non-malicious. It may be possible to make arbitrary changes to data structures, user information, or even process ownership.

Savunma

Nasıl önlenir ve çözülür?

Requirements

Güvenlik gereksinimi

Detay
Many contemporary languages have functions which properly handle this condition. Older C temp file functions are especially susceptible.

Implementation

Uygulama aşaması savunması

Detay
Ensure that you use proper file permissions. This can be achieved by using a safe temp file function. Temporary files should be writable and readable only by the process that owns the file.

Implementation

Uygulama aşaması savunması

Detay
Randomize temporary file names. This can also be achieved by using a safe temp-file function. This will ensure that temporary files will not be created in predictable places.

Doğrulama

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Automated Static Analysis

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.)