CWE-263 Base Draft Low likelihood

Password Aging with Long Expiration

The system enforces password changes, but the time allowed between changes is excessively long, weakening security.

Definition

What is CWE-263?

The system enforces password changes, but the time allowed between changes is excessively long, weakening security.
Password aging, or forced password rotation, is a security policy that requires users to update their passwords after a set period, like every 30 or 90 days. When this expiration window is too long, it gives attackers significantly more time to crack passwords through brute-force or dictionary attacks before a user is forced to change them. While password rotation was once a standard recommendation, many security experts now consider it less effective against modern threats compared to strong, slow hashing algorithms and multi-factor authentication. Forcing frequent changes can also lead to user fatigue, resulting in weaker, predictable passwords. However, this practice often remains in place to meet specific compliance requirements, such as those found in the PCI DSS standard.
Real-world impact

Real-world CVEs caused by CWE-263

No public CVE references are linked to this CWE in MITRE's catalog yet.

How attackers exploit it

Step-by-step attacker path

  1. 1

    Identify a code path that handles untrusted input without validation.

  2. 2

    Craft a payload that exercises the unsafe behavior — injection, traversal, overflow, or logic abuse.

  3. 3

    Deliver the payload through a normal request and observe the application's reaction.

  4. 4

    Iterate until the response leaks data, executes attacker code, or escalates privileges.

Vulnerable code example

Vulnerable pseudo

MITRE has not published a code example for this CWE. The pattern below is illustrative — see Resources for canonical references.

Vulnerable pseudo 
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
  // Untrusted input flows directly into the sensitive sink.
  return executeUnsafe(input);
}
Secure code example

Secure pseudo

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-263

  • Implementation Previously, "password expiration" was widely advocated as a defense-in-depth approach to minimize the risk of weak passwords, and it has become a common practice. Password expiration requires a password to be changed within a fixed time window (such as every 90 days). However, this approach has significant limitations in the current threat landscape, and its utility has been reduced in light of the adoption of related protection mechanisms (such as password complexity and computational effort), along with the recognition that regular password changes often caused users to generate more predictable passwords. As a result, this is now a Discouraged Common Practice [REF-1488] [REF-1489], especially as the sole factor in protecting passwords. It is still strongly encouraged to force password changes in case of evidence of compromise, but this is not the same as a forced "expiration" on an arbitrary time frame.
  • Architecture and Design Ensure that password aging is limited so that there is a defined maximum age for passwords. Note that if the expiration window is too short, it can cause users to generate poor or predictable passwords.
  • Architecture and Design Ensure that the user is notified several times leading up to the password expiration.
  • Architecture and Design Create mechanisms to prevent users from reusing passwords or creating similar passwords.
  • Implementation Developers might disable clipboard paste operations into password fields as a way to discourage users from pasting a password into a clipboard. However, this might encourage users to choose less-secure passwords that are easier to type, and it can reduce the usability of password managers [REF-1294].
Detection signals

How to detect CWE-263

SAST High

Run static analysis (SAST) on the codebase looking for the unsafe pattern in the data flow.

DAST Moderate

Run dynamic application security testing against the live endpoint.

Runtime Moderate

Watch runtime logs for unusual exception traces, malformed input, or authorization bypass attempts.

Code review Moderate

Code review: flag any new code that handles input from this surface without using the validated framework helpers.

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Frequently asked questions

Frequently asked questions

What is CWE-263?

The system enforces password changes, but the time allowed between changes is excessively long, weakening security.

How serious is CWE-263?

MITRE rates the likelihood of exploit as Low — exploitation is uncommon, but the weakness should still be fixed when discovered.

What languages or platforms are affected by CWE-263?

MITRE has not specified affected platforms for this CWE — it can apply across most application stacks.

How can I prevent CWE-263?

Previously, "password expiration" was widely advocated as a defense-in-depth approach to minimize the risk of weak passwords, and it has become a common practice. Password expiration requires a password to be changed within a fixed time window (such as every 90 days). However, this approach has significant limitations in the current threat landscape, and its utility has been reduced in light of the adoption of related protection mechanisms (such as password complexity and computational…

How does Plexicus detect and fix CWE-263?

Plexicus's SAST engine matches the data-flow signature for CWE-263 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-263?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/263.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-263

CWE-1390 Parent

Weak Authentication

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CWE-1391 Sibling

Use of Weak Credentials

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CWE-262 Sibling

Not Using Password Aging

This vulnerability occurs when a system lacks password expiration policies, allowing users to keep the same password indefinitely.

CWE-289 Sibling

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CWE-290 Sibling

Authentication Bypass by Spoofing

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CWE-294 Sibling

Authentication Bypass by Capture-replay

This vulnerability occurs when an attacker can intercept and record legitimate authentication traffic, then replay it later to gain…

CWE-301 Sibling

Reflection Attack in an Authentication Protocol

A reflection attack is a flaw in mutual authentication protocols that allows an attacker to impersonate a legitimate user without knowing…

CWE-302 Sibling

Authentication Bypass by Assumed-Immutable Data

This vulnerability occurs when an authentication system incorrectly treats certain data as unchangeable, when in fact an attacker can…

CWE-303 Sibling

Incorrect Implementation of Authentication Algorithm

This weakness occurs when a developer implements a standard authentication algorithm, but makes critical mistakes in the code that cause…

Resources

Further reading

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