CWE-308 Base Draft High likelihood

Use of Single-factor Authentication

Relying solely on single-factor authentication, like a password, exposes systems to significant security risks because it depends on only one type of proof for verifying a user's identity.

Definition

What is CWE-308?

Relying solely on single-factor authentication, like a password, exposes systems to significant security risks because it depends on only one type of proof for verifying a user's identity.
Single-factor authentication creates a single point of failure. Since passwords are often weak, reused, or stolen, a single breach can lead directly to full account compromise. Implementing a second factor, such as a code from an app or a hardware token, adds a critical layer of defense that drastically reduces this risk. While adding authentication methods increases complexity, the security benefit is substantial. For any application handling sensitive data, requiring multi-factor authentication (MFA) is a best practice. It should be implemented wherever feasible, especially when the additional factors are user-friendly and do not overly hinder the login experience.
Real-world impact

Real-world CVEs caused by CWE-308

  • CVE-2022-35248

    Chat application skips validation when Central Authentication Service (CAS) is enabled, effectively removing the second factor from two-factor authentication

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 C

In both of these examples, a user is logged in if their given password matches a stored password:

Vulnerable C 
unsigned char *check_passwd(char *plaintext) {
  	ctext = simple_digest("sha1",plaintext,strlen(plaintext), ... );
```
//Login if hash matches stored hash* 
  	if (equal(ctext, secret_password())) {
  	```
  		login_user();
  	}
  }
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-308

  • Architecture and Design Use multiple independent authentication schemes, which ensures that -- if one of the methods is compromised -- the system itself is still likely safe from compromise.
Detection signals

How to detect CWE-308

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.

Plexicus auto-fix

Plexicus auto-detects CWE-308 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.

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Frequently asked questions

Frequently asked questions

What is CWE-308?

Relying solely on single-factor authentication, like a password, exposes systems to significant security risks because it depends on only one type of proof for verifying a user's identity.

How serious is CWE-308?

MITRE rates the likelihood of exploit as High — this weakness is actively exploited in the wild and should be prioritized for remediation.

What languages or platforms are affected by CWE-308?

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

How can I prevent CWE-308?

Use multiple independent authentication schemes, which ensures that -- if one of the methods is compromised -- the system itself is still likely safe from compromise.

How does Plexicus detect and fix CWE-308?

Plexicus's SAST engine matches the data-flow signature for CWE-308 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-308?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/308.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-308

CWE-1390 Parent

Weak Authentication

This vulnerability occurs when a system's login or identity verification process is too easy to bypass or fool. While it attempts to check…

CWE-1391 Sibling

Use of Weak Credentials

This vulnerability occurs when a system relies on weak authentication credentials—like default passwords, hard-coded keys, or easily…

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-263 Sibling

Password Aging with Long Expiration

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

CWE-289 Sibling

Authentication Bypass by Alternate Name

This vulnerability occurs when a system checks access based on a resource or user name, but fails to account for all the different names…

CWE-290 Sibling

Authentication Bypass by Spoofing

This weakness occurs when an application's authentication system can be tricked into accepting forged or manipulated credentials, allowing…

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…

Resources

Further reading

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