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.)
CWE-269 Class Draft
Improper Privilege Management
This vulnerability occurs when an application fails to correctly manage user permissions, allowing someone to perform actions or access data beyond their intended authority.
Definition
What is CWE-269?
This vulnerability occurs when an application fails to correctly manage user permissions, allowing someone to perform actions or access data beyond their intended authority.
Improper privilege management is a core security flaw where the system's logic for granting, changing, or verifying user rights is broken. Instead of consistently enforcing a 'least privilege' model, it creates gaps where attackers or even regular users can escalate their access, modify settings, view sensitive information, or delete data they shouldn't touch. This often stems from flawed assumptions, missing checks, or errors in how roles and permissions are tracked throughout a user's session.
To prevent this, developers must implement a centralized, deny-by-default authorization layer that validates every request against the user's current, verified privileges. Key strategies include using server-side checks for all actions, avoiding reliance on client-side controls, implementing proper session management, and conducting regular audits of permission assignments. Always explicitly verify 'who can do what' at the point of every action, never assuming the user interface or a previous check is sufficient.
Real-world impact
Real-world CVEs caused by CWE-269
-
Terminal privileges are not reset when a user logs out.
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Does not properly pass security context to child processes in certain cases, allows privilege escalation.
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Does not properly compute roles.
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untrusted user placed in unix "wheel" group
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Product allows users to grant themselves certain rights that can be used to escalate privileges.
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Product uses group ID of a user instead of the group, causing it to run with different privileges. This is resultant from some other unknown issue.
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Product mistakenly assigns a particular status to an entity, leading to increased privileges.
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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.
How attackers exploit it
Step-by-step attacker path
- 1
This code temporarily raises the program's privileges to allow creation of a new user folder.
- 2
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.
- 3
The following example demonstrates the weakness.
- 4
The following example demonstrates the weakness.
- 5
This code intends to allow only Administrators to print debug information about a system.
Vulnerable code example
Vulnerable Python
This code temporarily raises the program's privileges to allow creation of a new user folder.
def makeNewUserDir(username):
if invalidUsername(username):
```
#avoid CWE-22 and CWE-78*
print('Usernames cannot contain invalid characters')
return False
try:
```
raisePrivileges()
os.mkdir('/home/' + username)
lowerPrivileges()
except OSError:
print('Unable to create new user directory for user:' + username)
return False
return True Secure code example
Secure pseudo
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
const safe = validateAndEscape(input);
return executeWithGuards(safe);
} What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Prevention checklist
How to prevent CWE-269
- Architecture and Design / Operation Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Architecture and Design Follow the principle of least privilege when assigning access rights to entities in a software system.
- Architecture and Design Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
Detection signals
How to detect CWE-269
Plexicus auto-detects CWE-269 and opens a fix PR in under 60 seconds.
Codex Remedium scans every commit, identifies this exact weakness, and ships a reviewer-ready pull request with the patch. No tickets. No hand-offs.
Frequently asked questions What is CWE-269?
How serious is CWE-269?
What languages or platforms are affected by CWE-269?
How can I prevent CWE-269?
How does Plexicus detect and fix CWE-269?
Where can I learn more about CWE-269?
Frequently asked questions
What is CWE-269?
This vulnerability occurs when an application fails to correctly manage user permissions, allowing someone to perform actions or access data beyond their intended authority.
How serious is CWE-269?
MITRE rates the likelihood of exploit as Medium — exploitation is realistic but typically requires specific conditions.
What languages or platforms are affected by CWE-269?
MITRE has not specified affected platforms for this CWE — it can apply across most application stacks.
How can I prevent CWE-269?
Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software. Follow the principle of least privilege when assigning access rights to entities in a software system.
How does Plexicus detect and fix CWE-269?
Plexicus's SAST engine matches the data-flow signature for CWE-269 on every commit. When a match is found, our Codex Remedium agent opens a fix PR with the corrected code, tests, and a one-line summary for the reviewer.
Where can I learn more about CWE-269?
MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/269.html. You can also reference OWASP and NIST documentation for adjacent guidance.
Related weaknesses
Weaknesses related to CWE-269
CWE-284 Parent
Improper Access Control
The software fails to properly limit who can access a resource, allowing unauthorized users or systems to interact with it.
CWE-1191 Sibling
On-Chip Debug and Test Interface With Improper Access Control
This vulnerability occurs when a hardware chip's debug or test interface (like JTAG) lacks proper access controls. Without correct…
CWE-1220 Sibling
Insufficient Granularity of Access Control
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CWE-1224 Sibling
Improper Restriction of Write-Once Bit Fields
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CWE-1231 Sibling
Improper Prevention of Lock Bit Modification
This vulnerability occurs when hardware or firmware uses a lock bit to protect critical system registers or memory regions, but fails to…
CWE-1233 Sibling
Security-Sensitive Hardware Controls with Missing Lock Bit Protection
This vulnerability occurs when a hardware device uses a lock bit to protect critical configuration registers, but the lock fails to…
CWE-1252 Sibling
CPU Hardware Not Configured to Support Exclusivity of Write and Execute Operations
This vulnerability occurs when a CPU's hardware is not set up to enforce a strict separation between writing data to memory and executing…
CWE-1257 Sibling
Improper Access Control Applied to Mirrored or Aliased Memory Regions
This vulnerability occurs when a hardware design maps the same physical memory to multiple addresses (aliasing or mirroring) but fails to…
CWE-1259 Sibling
Improper Restriction of Security Token Assignment
This vulnerability occurs when a System-on-a-Chip (SoC) fails to properly secure its Security Token mechanism. These tokens control which…
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