Tên: Operator Precedence Logic Error

The product uses an expression in which operator precedence causes incorrect logic to be used.

Thông tin chung

Các cách xuất hiện

Implementation : Logic errors related to operator precedence may cause problems even during normal operation, so they are probably discovered quickly during the testing phase. If testing is incomplete or there is a strong reliance on manual review of the code, then these errors may not be discovered before the software is deployed.

Nền tảng áp dụng

Ngôn ngữ

Lớp: Not Language-Specific (Rarely)
Tên: C (Rarely)
Tên: C++ (Rarely)
Tên: Python (Undetermined)

Hậu quả phổ biến

Phạm vi	Tác động	Khả năng xảy ra
Confidentiality Integrity Availability	Varies by Context, Unexpected State Ghi chú: While often just a bug, operator precedence logic errors can have serious consequences if they are used in security-critical code, such as making an authentication decision. The consequences will vary based on the context surrounding the incorrect precedence. In a security decision, violations of integrity or confidentiality are the most likely results. Otherwise, a crash may occur due to the software reaching an unexpected state.

Ví dụ đã quan sát

Tài liệu tham khảo	Mô tả
CVE-2026-7270	Chain: calculation expression does not use parentheses to address operator precedence (CWE-783), causing an incorrect calculation (CWE-682) leading to a buffer overflow (CWE-787).
CVE-2008-2516	Authentication module allows authentication bypass because it uses "(x = call(args) == SUCCESS)" instead of "((x = call(args)) == SUCCESS)".
CVE-2008-0599	Chain: Language interpreter calculates wrong buffer size (CWE-131) by using "size = ptr ? X : Y" instead of "size = (ptr ? X : Y)" expression.
CVE-2001-1155	Chain: product does not properly check the result of a reverse DNS lookup because of operator precedence (CWE-783), allowing bypass of DNS-based access restrictions.

Các biện pháp giảm thiểu tiềm năng

Phases : Implementation
Regularly wrap sub-expressions in parentheses, especially in security-critical code.

Phương pháp phát hiện

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.)
Hiệu quả : High

Ghi chú ánh xạ lỗ hổng

Lý do : This CWE entry is at the Base 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.

Tài liệu tham khảo

REF-704

EXP00-C. Use parentheses for precedence of operation
CERT.
https://www.securecoding.cert.org/confluence/display/seccode/EXP00-C.+Use+parentheses+for+precedence+of+operation

REF-62

The Art of Software Security Assessment
Mark Dowd, John McDonald, Justin Schuh.

REF-1534

Automated Technical Debt Measure, Version 2
OMG.
https://www.omg.org/spec/ATDM2/1.0/PDF

REF-1541

Secure Coding Guide for Python
OpenSSF.
https://best.openssf.org/Secure-Coding-Guide-for-Python/

Gửi

Tên	Tổ chức	Ngày	Ngày phát hành	Version
CWE Content Team	MITRE	2009-07-16 +00:00	2009-07-27 +00:00	1.5

Sửa đổi

Tên	Tổ chức	Ngày	Bình luận
CWE Content Team	MITRE	2009-12-28 +00:00	updated Observed_Examples
CWE Content Team	MITRE	2011-06-27 +00:00	updated Common_Consequences
CWE Content Team	MITRE	2012-05-11 +00:00	updated Demonstrative_Examples, References, Relationships
CWE Content Team	MITRE	2017-11-08 +00:00	updated Taxonomy_Mappings, Time_of_Introduction
CWE Content Team	MITRE	2019-01-03 +00:00	updated Taxonomy_Mappings
CWE Content Team	MITRE	2019-06-20 +00:00	updated Type
CWE Content Team	MITRE	2020-02-24 +00:00	updated Relationships
CWE Content Team	MITRE	2020-08-20 +00:00	updated Relationships
CWE Content Team	MITRE	2021-03-15 +00:00	updated Relationships
CWE Content Team	MITRE	2023-01-31 +00:00	updated Description
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 Detection_Factors, Weakness_Ordinalities
CWE Content Team	MITRE	2026-10-28 +00:00	updated Applicable_Platforms, Common_Consequences, Description, Observed_Examples, References, Relationships, Taxonomy_Mappings

Chi tiết CWE-783

CWE-783