Common Weakness Enumeration

CWE-522

Allowed-with-Review

Insufficiently Protected Credentials

Abstraction: Class · Status: Incomplete

The product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.

1820 vulnerabilities reference this CWE, most recent first.

GHSA-3435-G6FX-JC4P

Vulnerability from github – Published: 2026-04-02 21:32 – Updated: 2026-04-03 15:30
VLAI
Details

The stored API keys in temporary browser client is not marked as protected allowing for JavScript console or other errors to allow for extraction of the encryption credentials.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-35467"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-522"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-02T21:16:40Z",
    "severity": "HIGH"
  },
  "details": "The stored API keys in temporary browser client is not marked as protected allowing for JavScript console or other errors to allow for extraction of the encryption credentials.",
  "id": "GHSA-3435-g6fx-jc4p",
  "modified": "2026-04-03T15:30:30Z",
  "published": "2026-04-02T21:32:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-35467"
    },
    {
      "type": "WEB",
      "url": "https://github.com/CERTCC/cveClient/pull/39"
    },
    {
      "type": "WEB",
      "url": "https://github.com/CERTCC/cveClient"
    }
  ],
  "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-343Q-2M8H-67WF

Vulnerability from github – Published: 2022-02-11 00:00 – Updated: 2022-05-11 00:02
VLAI
Details

Insufficiently protected credentials in USB provisioning for Intel(R) AMT SDK before version 16.0.3, Intel(R) SCS before version 12.2 and Intel(R) MEBx before versions 11.0.0.0012, 12.0.0.0011, 14.0.0.0004 and 15.0.0.0004 may allow an unauthenticated user to potentially enable information disclosure via physical access.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2021-33107"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-522"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2022-02-09T23:15:00Z",
    "severity": "MODERATE"
  },
  "details": "Insufficiently protected credentials in USB provisioning for Intel(R) AMT SDK before version 16.0.3, Intel(R) SCS before version 12.2 and Intel(R) MEBx before versions 11.0.0.0012, 12.0.0.0011, 14.0.0.0004 and 15.0.0.0004 may allow an unauthenticated user to potentially enable information disclosure via physical access.",
  "id": "GHSA-343q-2m8h-67wf",
  "modified": "2022-05-11T00:02:20Z",
  "published": "2022-02-11T00:00:57Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-33107"
    },
    {
      "type": "WEB",
      "url": "https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00575.html"
    },
    {
      "type": "WEB",
      "url": "https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00601.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-346P-QX4X-G348

Vulnerability from github – Published: 2022-05-24 17:34 – Updated: 2022-05-24 17:34
VLAI
Details

Mutt before 2.0.2 and NeoMutt before 2020-11-20 did not ensure that $ssl_force_tls was processed if an IMAP server's initial server response was invalid. The connection was not properly closed, and the code could continue attempting to authenticate. This could result in authentication credentials being exposed on an unencrypted connection, or to a machine-in-the-middle.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2020-28896"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-522"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2020-11-23T19:15:00Z",
    "severity": "HIGH"
  },
  "details": "Mutt before 2.0.2 and NeoMutt before 2020-11-20 did not ensure that $ssl_force_tls was processed if an IMAP server\u0027s initial server response was invalid. The connection was not properly closed, and the code could continue attempting to authenticate. This could result in authentication credentials being exposed on an unencrypted connection, or to a machine-in-the-middle.",
  "id": "GHSA-346p-qx4x-g348",
  "modified": "2022-05-24T17:34:49Z",
  "published": "2022-05-24T17:34:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-28896"
    },
    {
      "type": "WEB",
      "url": "https://github.com/neomutt/neomutt/commit/9c36717a3e2af1f2c1b7242035455ec8112b4b06"
    },
    {
      "type": "WEB",
      "url": "https://github.com/neomutt/neomutt/releases/tag/20201120"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.com/muttmua/mutt/-/commit/04b06aaa3e0cc0022b9b01dbca2863756ebbf59a"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.com/muttmua/mutt/-/commit/d92689088dfe80a290ec836e292376e2d9984f8f"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2020/11/msg00048.html"
    },
    {
      "type": "WEB",
      "url": "https://security.gentoo.org/glsa/202101-32"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

GHSA-349X-PCH6-942W

Vulnerability from github – Published: 2022-05-24 17:01 – Updated: 2023-04-24 09:30
VLAI
Details

A flaw has been found in 389-ds-base versions 1.4.x.x before 1.4.1.3. When executed in verbose mode, the dscreate and dsconf commands may display sensitive information, such as the Directory Manager password. An attacker, able to see the screen or record the terminal standard error output, could use this flaw to gain sensitive information.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2019-10224"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-200",
      "CWE-522"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2019-11-25T16:15:00Z",
    "severity": "MODERATE"
  },
  "details": "A flaw has been found in 389-ds-base versions 1.4.x.x before 1.4.1.3. When executed in verbose mode, the dscreate and dsconf commands may display sensitive information, such as the Directory Manager password. An attacker, able to see the screen or record the terminal standard error output, could use this flaw to gain sensitive information.",
  "id": "GHSA-349x-pch6-942w",
  "modified": "2023-04-24T09:30:19Z",
  "published": "2022-05-24T17:01:51Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2019-10224"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-10224"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2023/04/msg00026.html"
    },
    {
      "type": "WEB",
      "url": "https://pagure.io/389-ds-base/issue/50251"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-34C4-3WV9-23CH

Vulnerability from github – Published: 2024-05-08 18:30 – Updated: 2024-05-08 18:30
VLAI
Details

Dell Update Manager Plugin, versions 1.4.0 through 1.5.0, contains a Plain-text Password Storage Vulnerability in Log file. A remote high privileged attacker could potentially exploit this vulnerability, leading to the disclosure of certain user credentials. The attacker may be able to use the exposed credentials to access the vulnerable application with privileges of the compromised account.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-28971"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-256",
      "CWE-522"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-05-08T16:15:08Z",
    "severity": "LOW"
  },
  "details": "Dell Update Manager Plugin, versions 1.4.0 through 1.5.0, contains a Plain-text Password Storage Vulnerability in Log file. A remote high privileged attacker could potentially exploit this vulnerability, leading to the disclosure of certain user credentials. The attacker may be able to use the exposed credentials to access the vulnerable application with privileges of the compromised account.",
  "id": "GHSA-34c4-3wv9-23ch",
  "modified": "2024-05-08T18:30:49Z",
  "published": "2024-05-08T18:30:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-28971"
    },
    {
      "type": "WEB",
      "url": "https://www.dell.com/support/kbdoc/en-us/000224849/dsa-2024-209-security-update-for-dell-update-manager-plugin-vulnerability"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-34QX-F7FF-W7XC

Vulnerability from github – Published: 2022-05-13 01:22 – Updated: 2022-05-13 01:22
VLAI
Details

Artica Proxy 3.06.200056 allows remote attackers to execute arbitrary commands as root by reading the ressources/settings.inc ldap_admin and ldap_password fields, using these credentials at logon.php, and then entering the commands in the admin.index.php command-line field.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2019-7300"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-522"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2019-02-01T09:29:00Z",
    "severity": "HIGH"
  },
  "details": "Artica Proxy 3.06.200056 allows remote attackers to execute arbitrary commands as root by reading the ressources/settings.inc ldap_admin and ldap_password fields, using these credentials at logon.php, and then entering the commands in the admin.index.php command-line field.",
  "id": "GHSA-34qx-f7ff-w7xc",
  "modified": "2022-05-13T01:22:49Z",
  "published": "2022-05-13T01:22:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2019-7300"
    },
    {
      "type": "WEB",
      "url": "https://code610.blogspot.com/2019/01/rce-in-artica.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com/c610/tmp/blob/master/aRtiCE.py"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-352F-RWJM-P38M

Vulnerability from github – Published: 2024-09-22 15:30 – Updated: 2024-09-22 15:30
VLAI
Details

IBM Cognos Analytics 11.2.0, 11.2.1, 11.2.2, 11.2.3, 11.2.4, 12.0.0, 12.0.1, 12.0.2, 12.0.3, and IBM Cognos Analytics Reports for iOS 11.0.0.7 could allow a local attacker to obtain sensitive information in the form of an API key. An attacker could use this information to launch further attacks against affected applications.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-40703"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-522"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-09-22T13:15:10Z",
    "severity": "MODERATE"
  },
  "details": "IBM Cognos Analytics 11.2.0, 11.2.1, 11.2.2, 11.2.3, 11.2.4, 12.0.0, 12.0.1, 12.0.2, 12.0.3, and IBM Cognos Analytics Reports for iOS 11.0.0.7 could allow a local attacker to obtain sensitive information in the form of an API key.  An attacker could use this information to launch further attacks against affected applications.",
  "id": "GHSA-352f-rwjm-p38m",
  "modified": "2024-09-22T15:30:34Z",
  "published": "2024-09-22T15:30:34Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40703"
    },
    {
      "type": "WEB",
      "url": "https://www.ibm.com/support/pages/node/7160700"
    },
    {
      "type": "WEB",
      "url": "https://www.ibm.com/support/pages/node/7168038"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-352V-HHMH-2W8H

Vulnerability from github – Published: 2023-05-16 18:30 – Updated: 2023-05-17 03:39
VLAI
Summary
Jenkins Code Dx Plugin displays API keys in plain text
Details

Jenkins Code Dx Plugin 3.1.0 and earlier stores Code Dx server API keys unencrypted in job config.xml files on the Jenkins controller as part of its configuration.

These API keys can be viewed by users with Item/Extended Read permission or access to the Jenkins controller file system.

Additionally, the job configuration form does not mask these API keys, increasing the potential for attackers to observe and capture them.

Code Dx Plugin 4.0.0 no longer stores the API keys directly, instead accessing them through its newly added Credentials Plugin integration. Affected jobs need to be reconfigured.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.jenkins-ci.plugins:codedx"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-2633"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-256",
      "CWE-522"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-05-17T03:39:07Z",
    "nvd_published_at": "2023-05-16T18:15:17Z",
    "severity": "MODERATE"
  },
  "details": "Jenkins Code Dx Plugin 3.1.0 and earlier stores Code Dx server API keys unencrypted in job `config.xml` files on the Jenkins controller as part of its configuration.\n\nThese API keys can be viewed by users with Item/Extended Read permission or access to the Jenkins controller file system.\n\nAdditionally, the job configuration form does not mask these API keys, increasing the potential for attackers to observe and capture them.\n\nCode Dx Plugin 4.0.0 no longer stores the API keys directly, instead accessing them through its newly added Credentials Plugin integration. Affected jobs need to be reconfigured.",
  "id": "GHSA-352v-hhmh-2w8h",
  "modified": "2023-05-17T03:39:07Z",
  "published": "2023-05-16T18:30:16Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-2633"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jenkinsci/codedx-plugin/commit/a971a75da3eaf0ab5344c2b60942e7c8809ec913"
    },
    {
      "type": "WEB",
      "url": "https://www.jenkins.io/security/advisory/2023-05-16/#SECURITY-3146"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Jenkins Code Dx Plugin displays API keys in plain text"
}

GHSA-356C-RCQ8-P23G

Vulnerability from github – Published: 2023-04-26 21:30 – Updated: 2024-04-04 03:42
VLAI
Details

Sangoma FreePBX 1805 through 2302 (when obtained as a ,.ISO file) places AMPDBUSER, AMPDBPASS, AMPMGRUSER, and AMPMGRPASS in the list of global variables. This exposes cleartext authentication credentials for the Asterisk Database (MariaDB/MySQL) and Asterisk Manager Interface. For example, an attacker can make a /ari/asterisk/variable?variable=AMPDBPASS API call.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2023-26567"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-522"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-04-26T20:15:09Z",
    "severity": "HIGH"
  },
  "details": "Sangoma FreePBX 1805 through 2302 (when obtained as a ,.ISO file) places AMPDBUSER, AMPDBPASS, AMPMGRUSER, and AMPMGRPASS in the list of global variables. This exposes cleartext authentication credentials for the Asterisk Database (MariaDB/MySQL) and Asterisk Manager Interface. For example, an attacker can make a /ari/asterisk/variable?variable=AMPDBPASS API call.",
  "id": "GHSA-356c-rcq8-p23g",
  "modified": "2024-04-04T03:42:00Z",
  "published": "2023-04-26T21:30:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-26567"
    },
    {
      "type": "WEB",
      "url": "https://qsecure.com.cy/resources/advisories/sangoma-freepbx-linux-insecure-permissions"
    },
    {
      "type": "WEB",
      "url": "https://www.freepbx.org"
    },
    {
      "type": "WEB",
      "url": "https://www.sangoma.com/products/open-source"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-3598-85VR-8F48

Vulnerability from github – Published: 2022-05-24 17:42 – Updated: 2022-05-24 17:42
VLAI
Details

IBM Maximo for Civil Infrastructure 7.6.2 could allow a user to obtain sensitive information due to insecure storeage of authentication credentials. IBM X-Force ID: 196621.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2021-20445"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-522"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-02-18T15:15:00Z",
    "severity": "MODERATE"
  },
  "details": "IBM Maximo for Civil Infrastructure 7.6.2 could allow a user to obtain sensitive information due to insecure storeage of authentication credentials. IBM X-Force ID: 196621.",
  "id": "GHSA-3598-85vr-8f48",
  "modified": "2022-05-24T17:42:37Z",
  "published": "2022-05-24T17:42:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-20445"
    },
    {
      "type": "WEB",
      "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/196621"
    },
    {
      "type": "WEB",
      "url": "https://www.ibm.com/support/pages/node/6415891"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

Mitigation
Architecture and Design

Use an appropriate security mechanism to protect the credentials.

Mitigation
Architecture and Design

Make appropriate use of cryptography to protect the credentials.

Mitigation
Implementation

Use industry standards to protect the credentials (e.g. LDAP, keystore, etc.).

CAPEC-102: Session Sidejacking

Session sidejacking takes advantage of an unencrypted communication channel between a victim and target system. The attacker sniffs traffic on a network looking for session tokens in unencrypted traffic. Once a session token is captured, the attacker performs malicious actions by using the stolen token with the targeted application to impersonate the victim. This attack is a specific method of session hijacking, which is exploiting a valid session token to gain unauthorized access to a target system or information. Other methods to perform a session hijacking are session fixation, cross-site scripting, or compromising a user or server machine and stealing the session token.

CAPEC-474: Signature Spoofing by Key Theft

An attacker obtains an authoritative or reputable signer's private signature key by theft and then uses this key to forge signatures from the original signer to mislead a victim into performing actions that benefit the attacker.

CAPEC-50: Password Recovery Exploitation

An attacker may take advantage of the application feature to help users recover their forgotten passwords in order to gain access into the system with the same privileges as the original user. Generally password recovery schemes tend to be weak and insecure.

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-551: Modify Existing Service

When an operating system starts, it also starts programs called services or daemons. Modifying existing services may break existing services or may enable services that are disabled/not commonly used.

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-560: Use of Known Domain Credentials

An adversary guesses or obtains (i.e. steals or purchases) legitimate credentials (e.g. userID/password) to achieve authentication and to perform authorized actions under the guise of an authenticated user or service.

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-600: Credential Stuffing

An adversary tries known username/password combinations against different systems, applications, or services to gain additional authenticated access. Credential Stuffing attacks rely upon the fact that many users leverage the same username/password combination for multiple systems, applications, and services.

CAPEC-644: Use of Captured Hashes (Pass The Hash)

An adversary obtains (i.e. steals or purchases) legitimate Windows domain credential hash values to access systems within the domain that leverage the Lan Man (LM) and/or NT Lan Man (NTLM) authentication protocols.

CAPEC-645: Use of Captured Tickets (Pass The Ticket)

An adversary uses stolen Kerberos tickets to access systems/resources that leverage the Kerberos authentication protocol. 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. An adversary can obtain any one of these tickets (e.g. Service Ticket, Ticket Granting Ticket, Silver Ticket, or Golden Ticket) to authenticate to a system/resource without needing the account's credentials. Depending on the ticket obtained, the adversary may be able to access a particular resource or generate TGTs for any account within an Active Directory Domain.

CAPEC-652: Use of Known Kerberos Credentials

An adversary obtains (i.e. steals or purchases) legitimate Kerberos credentials (e.g. Kerberos service account userID/password or Kerberos Tickets) with the goal of achieving authenticated access to additional systems, applications, or services within the domain.

CAPEC-653: Use of Known Operating System Credentials

An adversary guesses or obtains (i.e. steals or purchases) legitimate operating system credentials (e.g. userID/password) to achieve authentication and to perform authorized actions on the system, under the guise of an authenticated user or service. This applies to any Operating System.