CWE-269 Class Draft Medium likelihood

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.
Vulnerability Diagram CWE-269
Improper Privilege Management init setuid(root) bind :443 should drop setuid(www) ✗ forgotten handle requests still root → exploit = full system Privileges granted for setup are kept far longer than needed.
Auswirkungen in der Praxis

Real-world CVEs caused by CWE-269

  • Terminal privileges are not reset when a user logs out.

  • Does not properly pass security context to child processes in certain cases, allows privilege escalation.

  • Does not properly compute roles.

  • untrusted user placed in unix "wheel" group

  • Product allows users to grant themselves certain rights that can be used to escalate privileges.

  • 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.

  • Product mistakenly assigns a particular status to an entity, leading to increased privileges.

  • 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.

Wie Angreifer es ausnutzen

Angreiferpfad Schritt für Schritt

  1. 1

    This code temporarily raises the program's privileges to allow creation of a new user folder.

  2. 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. 3

    The following example demonstrates the weakness.

  4. 4

    The following example demonstrates the weakness.

  5. 5

    This code intends to allow only Administrators to print debug information about a system.

Verwundbares Codebeispiel

Vulnerable Python

This code temporarily raises the program's privileges to allow creation of a new user folder.

Verwundbar Python
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
Sicheres Codebeispiel

Secure pseudo

Sicher 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.
Präventions-Checkliste

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.
Erkennungssignale

How to detect CWE-269

Automated Static Analysis High

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.)

Plexicus Auto-Fix

Plexicus erkennt CWE-269 automatisch und öffnet in unter 60 Sekunden einen Fix-PR.

Codex Remedium scannt jeden Commit, identifiziert genau diese Schwachstelle und liefert einen reviewer-ready Pull Request mit dem Patch. Keine Tickets. Keine Hand-offs.

Häufig gestellte Fragen

Frequently asked questions

Was ist 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.

Wie gravierend ist CWE-269?

MITRE stuft die Exploit-Wahrscheinlichkeit als mittel ein — eine Ausnutzung ist realistisch, erfordert aber meist bestimmte Bedingungen.

Welche Sprachen oder Plattformen sind von CWE-269 betroffen?

MITRE hat für diese CWE keine betroffenen Plattformen spezifiziert — sie kann in den meisten Anwendungs-Stacks auftreten.

Wie kann ich CWE-269 verhindern?

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.

Wie erkennt und behebt Plexicus CWE-269?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-269 bei jedem Commit. Bei einem Treffer öffnet unser Codex-Remedium-Agent einen Fix-PR mit korrigiertem Code, Tests und einer einzeiligen Zusammenfassung für den Reviewer.

Wo erfahre ich mehr über CWE-269?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/269.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

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

This vulnerability occurs when a system's access controls are too broad, allowing unauthorized users or processes to read or modify…

CWE-1224 Sibling

Improper Restriction of Write-Once Bit Fields

This vulnerability occurs when hardware write-once protection mechanisms, often called 'sticky bits,' are incorrectly implemented,…

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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