CWE-521
AllowedWeak Password Requirements
Abstraction: Base · Status: Draft
The product does not require that users should have strong passwords.
351 vulnerabilities reference this CWE, most recent first.
GHSA-4P4M-5QP7-479X
Vulnerability from github – Published: 2023-03-31 03:30 – Updated: 2023-04-07 22:37Weak password requirements in GitHub repository thorsten/phpmyfaq prior to 3.1.12.
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "thorsten/phpmyfaq"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.12"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2023-1753"
],
"database_specific": {
"cwe_ids": [
"CWE-521"
],
"github_reviewed": true,
"github_reviewed_at": "2023-03-31T22:43:05Z",
"nvd_published_at": "2023-03-31T01:15:00Z",
"severity": "MODERATE"
},
"details": "Weak password requirements in GitHub repository thorsten/phpmyfaq prior to 3.1.12.",
"id": "GHSA-4p4m-5qp7-479x",
"modified": "2023-04-07T22:37:43Z",
"published": "2023-03-31T03:30:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-1753"
},
{
"type": "WEB",
"url": "https://github.com/thorsten/phpmyfaq/commit/f612a72494080e04947da7028340fee4493fe8a5"
},
{
"type": "PACKAGE",
"url": "https://github.com/thorsten/phpmyfaq"
},
{
"type": "WEB",
"url": "https://huntr.dev/bounties/01d6ae23-3a8f-42a8-99f4-10246187d71b"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "phpMyFAQ has weak password requirements"
}
GHSA-4P88-CFHQ-F3VG
Vulnerability from github – Published: 2023-01-16 00:30 – Updated: 2023-01-23 18:50Weak Password Requirements in GitHub repository thorsten/phpmyfaq prior to 3.1.10
{
"affected": [
{
"package": {
"ecosystem": "Packagist",
"name": "thorsten/phpmyfaq"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.10"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2023-0307"
],
"database_specific": {
"cwe_ids": [
"CWE-521"
],
"github_reviewed": true,
"github_reviewed_at": "2023-01-20T22:46:36Z",
"nvd_published_at": "2023-01-15T22:15:00Z",
"severity": "MODERATE"
},
"details": "Weak Password Requirements in GitHub repository thorsten/phpmyfaq prior to 3.1.10",
"id": "GHSA-4p88-cfhq-f3vg",
"modified": "2023-01-23T18:50:41Z",
"published": "2023-01-16T00:30:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-0307"
},
{
"type": "WEB",
"url": "https://github.com/thorsten/phpmyfaq/commit/8beed2fca5b0b82c6ba866d0ffd286d0c1fbf596"
},
{
"type": "PACKAGE",
"url": "https://github.com/thorsten/phpmyfaq"
},
{
"type": "WEB",
"url": "https://huntr.dev/bounties/fac01e9f-e3e5-4985-94ad-59a76485f215"
}
],
"schema_version": "1.4.0",
"severity": [],
"summary": "phpMyFAQ has Weak Password Requirements"
}
GHSA-4QVJ-3P36-QXPV
Vulnerability from github – Published: 2023-05-10 06:30 – Updated: 2024-04-04 03:58Use of weak credentials exists in SkyBridge MB-A100/110 firmware Ver. 4.2.0 and earlier, which may allow a remote unauthenticated attacker to decrypt password for the WebUI of the product.
{
"affected": [],
"aliases": [
"CVE-2023-25072"
],
"database_specific": {
"cwe_ids": [
"CWE-521"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-05-10T06:15:13Z",
"severity": "HIGH"
},
"details": "Use of weak credentials exists in SkyBridge MB-A100/110 firmware Ver. 4.2.0 and earlier, which may allow a remote unauthenticated attacker to decrypt password for the WebUI of the product.",
"id": "GHSA-4qvj-3p36-qxpv",
"modified": "2024-04-04T03:58:32Z",
"published": "2023-05-10T06:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-25072"
},
{
"type": "WEB",
"url": "https://jvn.jp/en/jp/JVN40604023"
},
{
"type": "WEB",
"url": "https://www.seiko-sol.co.jp/archives/73969"
},
{
"type": "WEB",
"url": "https://www.seiko-sol.co.jp/products/skybridge/skybridge_download/mb-a100"
},
{
"type": "WEB",
"url": "https://www.seiko-sol.co.jp/products/skybridge/skybridge_download/mb-a130"
},
{
"type": "WEB",
"url": "https://www.seiko-sol.co.jp/products/skybridge/skybridge_download/mb-a200"
},
{
"type": "WEB",
"url": "https://www.seiko-sol.co.jp/products/skyspider/skyspider_download/mb-r210"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-4R8H-X6H9-22VX
Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-05-27 15:33IBM Operations Analytics - Log Analysis 1.3.5.0, 1.3.5.1, 1.3.5.2, 1.3.5.3, 1.3.6.0, 1.3.6.1, 1.3.7.0, 1.3.7.1, 1.3.7.2, and 1.3.8.0, 1.3.8.1, 1.3.8.2, 1.3.8.3, 1.3.8.4 IBM SmartCloud Analytics - Log Analysis does not require that users should have strong passwords by default, which makes it easier for attackers to compromise user accounts.
{
"affected": [],
"aliases": [
"CVE-2024-40684"
],
"database_specific": {
"cwe_ids": [
"CWE-521"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-27T14:16:40Z",
"severity": "MODERATE"
},
"details": "IBM Operations Analytics - Log Analysis 1.3.5.0, 1.3.5.1, 1.3.5.2, 1.3.5.3, 1.3.6.0, 1.3.6.1, 1.3.7.0, 1.3.7.1, 1.3.7.2, and 1.3.8.0, 1.3.8.1, 1.3.8.2, 1.3.8.3, 1.3.8.4 IBM SmartCloud Analytics - Log Analysis does not require that users should have strong passwords by default, which makes it easier for attackers to compromise user accounts.",
"id": "GHSA-4r8h-x6h9-22vx",
"modified": "2026-05-27T15:33:10Z",
"published": "2026-05-27T15:33:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40684"
},
{
"type": "WEB",
"url": "https://www.ibm.com/support/pages/node/7268536"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-4RJ2-9GCX-5QHX
Vulnerability from github – Published: 2025-03-20 12:32 – Updated: 2025-04-09 20:06In mlflow/mlflow version 2.18, an admin is able to create a new user account without setting a password. This vulnerability could lead to security risks, as accounts without passwords may be susceptible to unauthorized access. Additionally, this issue violates best practices for secure user account management. The issue is fixed in version 2.19.0.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "mlflow"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.19.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-1474"
],
"database_specific": {
"cwe_ids": [
"CWE-521"
],
"github_reviewed": true,
"github_reviewed_at": "2025-03-21T23:36:26Z",
"nvd_published_at": "2025-03-20T10:15:54Z",
"severity": "LOW"
},
"details": "In mlflow/mlflow version 2.18, an admin is able to create a new user account without setting a password. This vulnerability could lead to security risks, as accounts without passwords may be susceptible to unauthorized access. Additionally, this issue violates best practices for secure user account management. The issue is fixed in version 2.19.0.",
"id": "GHSA-4rj2-9gcx-5qhx",
"modified": "2025-04-09T20:06:06Z",
"published": "2025-03-20T12:32:53Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-1474"
},
{
"type": "WEB",
"url": "https://github.com/mlflow/mlflow/commit/149c9e18aa219bc47e86b432e130e467a36f4a17"
},
{
"type": "PACKAGE",
"url": "https://github.com/mlflow/mlflow"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/mlflow/PYSEC-2025-17.yaml"
},
{
"type": "WEB",
"url": "https://huntr.com/bounties/e79f7774-10fe-46b2-b522-e73b748e3b2d"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "MLflow has Weak Password Requirements"
}
GHSA-4X33-7VP7-CQ3R
Vulnerability from github – Published: 2022-05-13 01:50 – Updated: 2022-05-13 01:50An issue was discovered on Foscam C2 devices with System Firmware 1.11.1.8 and Application Firmware 2.72.1.32, and Opticam i5 devices with System Firmware 1.5.2.11 and Application Firmware 2.21.1.128. The ftpuser1 account has a blank password, which cannot be changed.
{
"affected": [],
"aliases": [
"CVE-2018-19064"
],
"database_specific": {
"cwe_ids": [
"CWE-521"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-11-07T18:29:00Z",
"severity": "CRITICAL"
},
"details": "An issue was discovered on Foscam C2 devices with System Firmware 1.11.1.8 and Application Firmware 2.72.1.32, and Opticam i5 devices with System Firmware 1.5.2.11 and Application Firmware 2.21.1.128. The ftpuser1 account has a blank password, which cannot be changed.",
"id": "GHSA-4x33-7vp7-cq3r",
"modified": "2022-05-13T01:50:47Z",
"published": "2022-05-13T01:50:47Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-19064"
},
{
"type": "WEB",
"url": "https://sintonen.fi/advisories/foscam-ip-camera-multiple-vulnerabilities.txt"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-5257-G4X8-28QJ
Vulnerability from github – Published: 2024-09-26 18:31 – Updated: 2024-09-26 18:31In the goTenna Pro ATAK Plugin application, the encryption keys are stored along with a static IV on the device. This allows for complete decryption of keys stored on the device. This allows an attacker to decrypt all encrypted broadcast communications based on broadcast keys stored on the device.
{
"affected": [],
"aliases": [
"CVE-2024-45374"
],
"database_specific": {
"cwe_ids": [
"CWE-521",
"CWE-922"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-09-26T18:15:07Z",
"severity": "MODERATE"
},
"details": "In the goTenna Pro ATAK Plugin application, the encryption keys are \nstored along with a static IV on the device. This allows for complete \ndecryption of keys stored on the device. This allows an attacker to \ndecrypt all encrypted broadcast communications based on broadcast keys \nstored on the device.",
"id": "GHSA-5257-g4x8-28qj",
"modified": "2024-09-26T18:31:45Z",
"published": "2024-09-26T18:31:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-45374"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/news-events/ics-advisories/icsa-24-270-05"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-526H-6368-HCF5
Vulnerability from github – Published: 2025-10-24 21:31 – Updated: 2025-10-24 21:31Microweber CMS 2.0 has Weak Password Requirements. The application does not enforce minimum password length or complexity during password resets. Users can set extremely weak passwords, including single-character passwords, which can lead to account compromise, including administrative accounts.
{
"affected": [],
"aliases": [
"CVE-2025-60954"
],
"database_specific": {
"cwe_ids": [
"CWE-521"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-24T21:16:03Z",
"severity": "HIGH"
},
"details": "Microweber CMS 2.0 has Weak Password Requirements. The application does not enforce minimum password length or complexity during password resets. Users can set extremely weak passwords, including single-character passwords, which can lead to account compromise, including administrative accounts.",
"id": "GHSA-526h-6368-hcf5",
"modified": "2025-10-24T21:31:11Z",
"published": "2025-10-24T21:31:11Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-60954"
},
{
"type": "WEB",
"url": "https://gist.github.com/progprnv/feae2b76f2db0cb2ac6e14b1bf7d8646"
},
{
"type": "WEB",
"url": "https://github.com/microweber/microweber"
},
{
"type": "WEB",
"url": "https://github.com/progprnv/CVE-Reports/blob/main/CVE-2025-60954"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-556J-VP5W-5QJ6
Vulnerability from github – Published: 2022-05-24 16:56 – Updated: 2024-04-04 01:58RSA Archer, versions prior to 6.6 P2 (6.6.0.2), contain an improper authentication vulnerability. The vulnerability allows sysadmins to create user accounts with insufficient credentials. Unauthenticated attackers could gain unauthorized access to the system using those accounts.
{
"affected": [],
"aliases": [
"CVE-2019-3758"
],
"database_specific": {
"cwe_ids": [
"CWE-288",
"CWE-521"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2019-09-18T23:15:00Z",
"severity": "CRITICAL"
},
"details": "RSA Archer, versions prior to 6.6 P2 (6.6.0.2), contain an improper authentication vulnerability. The vulnerability allows sysadmins to create user accounts with insufficient credentials. Unauthenticated attackers could gain unauthorized access to the system using those accounts.",
"id": "GHSA-556j-vp5w-5qj6",
"modified": "2024-04-04T01:58:21Z",
"published": "2022-05-24T16:56:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2019-3758"
},
{
"type": "WEB",
"url": "https://community.rsa.com/docs/DOC-106759"
},
{
"type": "WEB",
"url": "https://www.dell.com/support/security/en-us/details/DOC-106759/DSA-2019-127-RSA-Archer-Security-Update-for-Multiple-Vulnerabilities"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-597M-G6CH-MRF9
Vulnerability from github – Published: 2024-01-30 15:30 – Updated: 2024-01-30 15:30Weak password requirement vulnerability
in Lamassu Bitcoin ATM Douro machines, in its 7.1 version
, which allows a local user to interact with the machine where the application is installed, retrieve stored hashes from the machine and crack long 4-character passwords using a dictionary attack.
{
"affected": [],
"aliases": [
"CVE-2024-0676"
],
"database_specific": {
"cwe_ids": [
"CWE-521"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-01-30T13:15:08Z",
"severity": "MODERATE"
},
"details": "Weak password requirement vulnerability \n\nin Lamassu Bitcoin ATM Douro machines, in its 7.1 version\n\n, which allows a local user to interact with the machine where the application is installed, retrieve stored hashes from the machine and crack long 4-character passwords using a dictionary attack.",
"id": "GHSA-597m-g6ch-mrf9",
"modified": "2024-01-30T15:30:22Z",
"published": "2024-01-30T15:30:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-0676"
},
{
"type": "WEB",
"url": "https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-lamassu-bitcoin-atm-douro-machines"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:P/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
Mitigation
- A product's design should require adherance to an appropriate password policy. Specific password requirements depend strongly on contextual factors, but it is recommended to contain the following attributes:
- Depending on the threat model, the password policy may include several additional attributes.
- See NIST 800-63B [REF-1053] for further information on password requirements.
- {'xhtml:li': ['Enforcement of a minimum and maximum length', 'Restrictions against password reuse', 'Restrictions against using common passwords', 'Restrictions against using contextual string in the password (e.g., user id, app name)']}
- {'xhtml:li': [{'xhtml:ul': {'xhtml:li': ['Increasing the range of characters makes the password harder to crack and may be appropriate for systems relying on single factor authentication.', 'Unfortunately, a complex password may be difficult to memorize, encouraging a user to select a short password or to incorrectly manage the password (write it down).', "Another disadvantage of this approach is that it often does not result in a significant increases in overal password complexity due to people's predictable usage of various symbols."]}, '#text': 'Complex passwords requiring mixed character sets (alpha, numeric, special, mixed case)'}, {'xhtml:ul': {'xhtml:li': ['Increasing the number of characters makes the password harder to crack and may be appropriate for systems relying on single factor authentication.', 'A disadvantage of this approach is that selecting a good passphrase is not easy and poor passwords can still be generated. Some prompting may be needed to encourage long un-predictable passwords.']}, '#text': 'Large Minimum Length (encouraging passphrases instead of passwords)'}, {'xhtml:ul': {'xhtml:li': ['Generating a password for the user can help make sure that length and complexity requirements are met, and can result in secure passwords being used.', 'A disadvantage of this approach is that the resulting password or passpharse may be too difficult to memorize, encouraging them to be written down.']}, '#text': 'Randomly Chosen Secrets'}]}
Mitigation
Consider a second authentication factor beyond the password, which prevents the password from being a single point of failure. See CWE-308 for further information.
Mitigation
Consider implementing a password complexity meter to inform users when a chosen password meets the required attributes.
Mitigation
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.
CAPEC-112: Brute Force
In this attack, some asset (information, functionality, identity, etc.) is protected by a finite secret value. The attacker attempts to gain access to this asset by using trial-and-error to exhaustively explore all the possible secret values in the hope of finding the secret (or a value that is functionally equivalent) that will unlock the asset.
CAPEC-16: Dictionary-based Password Attack
An attacker tries each of the words in a dictionary as passwords to gain access to the system via some user's account. If the password chosen by the user was a word within the dictionary, this attack will be successful (in the absence of other mitigations). This is a specific instance of the password brute forcing attack pattern.
Dictionary Attacks differ from similar attacks such as Password Spraying (CAPEC-565) and Credential Stuffing (CAPEC-600), since they leverage unknown username/password combinations and don't care about inducing account lockouts.
CAPEC-49: Password Brute Forcing
An adversary tries every possible value for a password until they succeed. A brute force attack, if feasible computationally, will always be successful because it will essentially go through all possible passwords given the alphabet used (lower case letters, upper case letters, numbers, symbols, etc.) and the maximum length of the password.
CAPEC-509: Kerberoasting
Through the exploitation of how service accounts leverage Kerberos authentication with Service Principal Names (SPNs), the adversary obtains and subsequently cracks the hashed credentials of a service account target to exploit its privileges. The Kerberos authentication protocol centers around a ticketing system which is used to request/grant access to services and to then access the requested services. As an authenticated user, the adversary may request Active Directory and obtain a service ticket with portions encrypted via RC4 with the private key of the authenticated account. By extracting the local ticket and saving it disk, the adversary can brute force the hashed value to reveal the target account credentials.
CAPEC-55: Rainbow Table Password Cracking
An attacker gets access to the database table where hashes of passwords are stored. They then use a rainbow table of pre-computed hash chains to attempt to look up the original password. Once the original password corresponding to the hash is obtained, the attacker uses the original password to gain access to the system.
CAPEC-555: Remote Services with Stolen Credentials
This pattern of attack involves an adversary that uses stolen credentials to leverage remote services such as RDP, telnet, SSH, and VNC to log into a system. Once access is gained, any number of malicious activities could be performed.
CAPEC-561: Windows Admin Shares with Stolen Credentials
An adversary guesses or obtains (i.e. steals or purchases) legitimate Windows administrator credentials (e.g. userID/password) to access Windows Admin Shares on a local machine or within a Windows domain.
CAPEC-565: Password Spraying
In a Password Spraying attack, an adversary tries a small list (e.g. 3-5) of common or expected passwords, often matching the target's complexity policy, against a known list of user accounts to gain valid credentials. The adversary tries a particular password for each user account, before moving onto the next password in the list. This approach assists the adversary in remaining undetected by avoiding rapid or frequent account lockouts. The adversary may then reattempt the process with additional passwords, once enough time has passed to prevent inducing a lockout.
CAPEC-70: Try Common or Default Usernames and Passwords
An adversary may try certain common or default usernames and passwords to gain access into the system and perform unauthorized actions. An adversary may try an intelligent brute force using empty passwords, known vendor default credentials, as well as a dictionary of common usernames and passwords. Many vendor products come preconfigured with default (and thus well-known) usernames and passwords that should be deleted prior to usage in a production environment. It is a common mistake to forget to remove these default login credentials. Another problem is that users would pick very simple (common) passwords (e.g. "secret" or "password") that make it easier for the attacker to gain access to the system compared to using a brute force attack or even a dictionary attack using a full dictionary.