Tên: Improper Neutralization of Variable Name Delimiters

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as variable name delimiters when they are sent to a downstream component, such as a "$" that could be used to access an environment variable.

Thông tin chung

Các cách xuất hiện

Implementation

Nền tảng áp dụng

Ngôn ngữ

Lớp: Not Language-Specific (Undetermined)

Hậu quả phổ biến

Phạm vi	Tác động	Khả năng xảy ra
Integrity	Unexpected State, Varies by Context Ghi chú: As data is parsed, an injected element may cause the process to take unexpected actions.

Ví dụ đã quan sát

Tài liệu tham khảo	Mô tả
CVE-2005-0129	"%" variable is expanded by wildcard function into disallowed commands.
CVE-2002-0770	Server trusts client to expand macros, allows macro characters to be expanded to trigger resultant information exposure.

Các biện pháp giảm thiểu tiềm năng

Developers should anticipate that variable name delimiters will be injected/removed/manipulated in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
Phases : Implementation
Phases : Implementation
While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or white space). If some special characters are still needed, such as white space, wrap each argument in quotes after the escaping/filtering step. Be careful of argument injection (CWE-88).
Phases : Implementation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

Ghi chú ánh xạ lỗ hổng

Lý do : This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Bình luận : Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

Mẫu tấn công liên quan

ID CAPEC	Tên mẫu tấn công
CAPEC-15	Command Delimiters An attack of this type exploits a programs' vulnerabilities that allows an attacker's commands to be concatenated onto a legitimate command with the intent of targeting other resources such as the file system or database. The system that uses a filter or denylist input validation, as opposed to allowlist validation is vulnerable to an attacker who predicts delimiters (or combinations of delimiters) not present in the filter or denylist. As with other injection attacks, the attacker uses the command delimiter payload as an entry point to tunnel through the application and activate additional attacks through SQL queries, shell commands, network scanning, and so on.

Ghi chú

Under-studied.

Gửi

Tên	Tổ chức	Ngày	Ngày phát hành	Version
PLOVER		2006-07-19 +00:00	2006-07-19 +00:00	Draft 3

Sửa đổi

Tên	Tổ chức	Ngày	Bình luận
Eric Dalci	Cigital	2008-07-01 +00:00	updated Potential_Mitigations, Time_of_Introduction
CWE Content Team	MITRE	2008-09-08 +00:00	updated Relationships, Taxonomy_Mappings
CWE Content Team	MITRE	2008-10-14 +00:00	updated Description
CWE Content Team	MITRE	2009-03-10 +00:00	updated Description, Name
CWE Content Team	MITRE	2009-07-27 +00:00	updated Potential_Mitigations
CWE Content Team	MITRE	2010-04-05 +00:00	updated Description, Name
CWE Content Team	MITRE	2011-03-29 +00:00	updated Observed_Examples, Potential_Mitigations
CWE Content Team	MITRE	2011-06-01 +00:00	updated Common_Consequences
CWE Content Team	MITRE	2011-06-27 +00:00	updated Common_Consequences
CWE Content Team	MITRE	2012-05-11 +00:00	updated Relationships
CWE Content Team	MITRE	2012-10-30 +00:00	updated Potential_Mitigations
CWE Content Team	MITRE	2014-07-30 +00:00	updated Relationships, Taxonomy_Mappings
CWE Content Team	MITRE	2017-05-03 +00:00	updated Potential_Mitigations
CWE Content Team	MITRE	2017-11-08 +00:00	updated Applicable_Platforms
CWE Content Team	MITRE	2020-02-24 +00:00	updated Potential_Mitigations, Relationships
CWE Content Team	MITRE	2020-06-25 +00:00	updated Potential_Mitigations
CWE Content Team	MITRE	2023-01-31 +00:00	updated Description, Potential_Mitigations
CWE Content Team	MITRE	2023-04-27 +00:00	updated Relationships
CWE Content Team	MITRE	2023-06-29 +00:00	updated Mapping_Notes
CWE Content Team	MITRE	2025-12-11 +00:00	updated Weakness_Ordinalities
CWE Content Team	MITRE	2026-10-28 +00:00	updated Common_Consequences, Description

Chi tiết CWE-154

CWE-154