CWE-250: Execution with Unnecessary Privileges
The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.
View on MITRETechnical Details
- Structure
- Simple
Applicable To
Security Consequences
Scope
Impact
An attacker will be able to gain access to any resources that are allowed by the extra privileges. Common results include executing code, disabling services, and reading restricted data. New weaknesses can be exposed because running with extra privileges, such as root or Administrator, can disable the normal security checks being performed by the operating system or surrounding environment. Other pre-existing weaknesses can turn into security vulnerabilities if they occur while operating at raised privileges.
Mitigation Strategies
Phase
Description
Perform extensive input validation for any privileged code that must be exposed to the user and reject anything that does not fit your strict requirements.
Phase
Description
If circumstances force you to run with extra privileges, then determine the minimum access level necessary. First identify the different permissions that the software and its users will need to perform their actions, such as file read and write permissions, network socket permissions, and so forth. Then explicitly allow those actions while denying all else [REF-76]. Perform extensive input validation and canonicalization to minimize the chances of introducing a separate vulnerability. This mitigation is much more prone to error than dropping the privileges in the first place.
Detection Methods
Method
Manual AnalysisDescription
This weakness can be detected using tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session.
Method
Automated Static Analysis - Binary or BytecodeDescription
According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Compare binary / bytecode to application permission manifest Cost effective for partial coverage: Bytecode Weakness Analysis - including disassembler + source code weakness analysis Binary Weakness Analysis - including disassembler + source code weakness analysis
Effectiveness
HighMethod
Manual Static Analysis - Source CodeDescription
According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Manual Source Code Review (not inspections) Cost effective for partial coverage: Focused Manual Spotcheck - Focused manual analysis of source
Effectiveness
HighMethod
Architecture or Design ReviewDescription
According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.) Formal Methods / Correct-By-Construction Cost effective for partial coverage: Attack Modeling
Effectiveness
HighCode Examples & CVEs
Demonstrative Examples
This code temporarily raises the program's privileges to allow creation of a new user folder.
While the program only raises its privilege level to create the folder and immediately lowers it again, if the call to os.mkdir() throws an exception, the call to lowerPrivileges() will not occur. As a result, the program is indefinitely operating in a raised privilege state, possibly allowing further exploitation to occur.
The following code calls chroot() to restrict the application to a subset of the filesystem below APP_HOME in order to prevent an attacker from using the program to gain unauthorized access to files located elsewhere. The code then opens a file specified by the user and processes the contents of the file.
Constraining the process inside the application's home directory before opening any files is a valuable security measure. However, the absence of a call to setuid() with some non-zero value means the application is continuing to operate with unnecessary root privileges. Any successful exploit carried out by an attacker against the application can now result in a privilege escalation attack because any malicious operations will be performed with the privileges of the superuser. If the application drops to the privilege level of a non-root user, the potential for damage is substantially reduced.
This application intends to use a user's location to determine the timezone the user is in:
This is unnecessary use of the location API, as this information is already available using the Android Time API. Always be sure there is not another way to obtain needed information before resorting to using the location API.
This code uses location to determine the user's current US State location.
First the application must declare that it requires the ACCESS_FINE_LOCATION permission in the application's manifest.xml:
This code uses location to determine the user's current US State location.
First the application must declare that it requires the ACCESS_FINE_LOCATION permission in the application's manifest.xml:
Observed CVE Examples (9)
FTP client program on a certain OS runs with setuid privileges and has a buffer overflow. Most clients do not need extra privileges, so an overflow is not a vulnerability for those clients.
View DetailsProgram runs with privileges and calls another program with the same privileges, which allows read of arbitrary files.
View DetailsOS incorrectly installs a program with setuid privileges, allowing users to gain privileges.
View DetailsComposite: application running with high privileges (CWE-250) allows user to specify a restricted file to process, which generates a parsing error that leaks the contents of the file (CWE-209).
View DetailsProgram does not drop privileges before calling another program, allowing code execution.
View Detailssetuid root program allows creation of arbitrary files through command line argument.
View DetailsInstallation script installs some programs as setuid when they shouldn't be.
View Detailsmail program runs as root but does not drop its privileges before attempting to access a file. Attacker can use a symlink from their home directory to a directory only readable by root, then determine whether the file exists based on the response.
View DetailsProduct launches Help functionality while running with raised privileges, allowing command execution using Windows message to access "open file" dialog.
View DetailsCWE Relationships
No relationship information available for this CWE.
Frequently Asked Questions
What is CWE-250: Execution with Unnecessary Privileges?+
CWE-250: Execution with Unnecessary Privileges is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.
What are the security consequences of Execution with Unnecessary Privileges?+
If exploited, CWE-250 (Execution with Unnecessary Privileges) it can compromise Confidentiality, Integrity, Availability and Access Control, leading to outcomes such as Gain Privileges or Assume Identity, Execute Unauthorized Code or Commands, Read Application Data and DoS: Crash, Exit, or Restart.
How do you prevent or mitigate Execution with Unnecessary Privileges?+
Recommended mitigations for CWE-250 include: Perform extensive input validation for any privileged code that must be exposed to the user and reject anything that does not fit your strict requirements. If circumstances force you to run with extra privileges, then determine the minimum access level necessary. First identify the different permissions that the software and its users will need to perform their actions, such as file read and write permissions, network socket permissions, and so forth. Then explicitly allow those actions while denying all else [REF-76]. Perform extensive input validation and canonicalization to minimize the chances of introducing a separate vulnerability. This mitigation is much more prone to error than dropping the privileges in the first place.
How is Execution with Unnecessary Privileges detected?+
CWE-250 can be detected using Manual Analysis, Automated Static Analysis - Binary or Bytecode, Manual Static Analysis - Source Code and Architecture or Design Review. Combining automated tooling with manual review typically yields the best coverage.
Which programming languages are affected by Execution with Unnecessary Privileges?+
CWE-250 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.
What are real-world examples of Execution with Unnecessary Privileges?+
MITRE documents real CVEs mapped to CWE-250, including CVE-2007-4217, CVE-2008-1877, CVE-2007-5159, CVE-2008-4638 and CVE-2008-0162. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.
What is the difference between a CWE and a CVE?+
A CWE (Common Weakness Enumeration) like CWE-250 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.