CWE WEAKNESSES  /  CWE-250

CWE-250

Execution with Unnecessary Privileges

What it is

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.

Impact

Mitigations

• [Architecture and Design, Operation] Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database ad
• [Architecture and Design] Identify the functionality that requires additional privileges, such as access to privileged operating system resources. Wrap and centralize this functionality if possible, and isolate the privileged code as much as possible from other code [REF-76]. Raise privileges as late as possible, and drop them as soon as possible to avoid CWE-271. Avoid weaknesses such as CWE-288 and CWE-420 by protecting
• [Architecture and Design] Identify the functionality that requires additional privileges, such as access to privileged operating system resources. Wrap and centralize this functionality if possible, and isolate the privileged code as much as possible from other code [REF-76]. Raise privileges as late as possible, and drop them as soon as possible to avoid CWE-271. Avoid weaknesses such as CWE-288 and CWE-420 by protecting
• [Implementation] 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.
• [Implementation] When dropping privileges, ensure that they have been dropped successfully to avoid CWE-273. As protection mechanisms in the environment get stronger, privilege-dropping calls may fail even if it seems like they would always succeed.
• [Implementation] 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 validat
• [Operation, System Configuration] Ensure that the software runs properly under the United States Government Configuration Baseline (USGCB) [REF-199] or an equivalent hardening configuration guide, which many organizations use to limit the attack surface and potential risk of deployed software.

Real-world CVE examples

• CVE-2007-4217 — 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 vul
• CVE-2008-1877 — Program runs with privileges and calls another program with the same privileges, which allows read of arbitrary files.
• CVE-2007-5159 — OS incorrectly installs a program with setuid privileges, allowing users to gain privileges.
• CVE-2008-4638 — Composite: application running with high privileges (CWE-250) allows user to specify a restricted file to process, which generates a parsing error that leaks th
• CVE-2008-0162 — Program does not drop privileges before calling another program, allowing code execution.
• CVE-2008-0368 — setuid root program allows creation of arbitrary files through command line argument.
• CVE-2007-3931 — Installation script installs some programs as setuid when they shouldn't be.
• CVE-2020-3812 — mail 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 directo
• CVE-2003-0908 — Product launches Help functionality while running with raised privileges, allowing command execution using Windows message to access "open file" dialog.

Related weaknesses

Source: MITRE CWE. View on cwe.mitre.org →