Common Weakness Enumeration

CWE-190

Allowed

Integer Overflow or Wraparound

Abstraction: Base · Status: Stable

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

3870 vulnerabilities reference this CWE, most recent first.

GHSA-FRX6-6WJG-8W2P

Vulnerability from github – Published: 2025-09-09 18:31 – Updated: 2025-09-09 18:31
VLAI
Details

Integer overflow or wraparound in Windows Kernel allows an authorized attacker to elevate privileges locally.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2025-54110"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-09-09T17:15:56Z",
    "severity": "HIGH"
  },
  "details": "Integer overflow or wraparound in Windows Kernel allows an authorized attacker to elevate privileges locally.",
  "id": "GHSA-frx6-6wjg-8w2p",
  "modified": "2025-09-09T18:31:21Z",
  "published": "2025-09-09T18:31:21Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-54110"
    },
    {
      "type": "WEB",
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-54110"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-FV4P-HRVC-C34G

Vulnerability from github – Published: 2024-07-08 18:31 – Updated: 2024-07-09 18:30
VLAI
Details

tap-windows6 driver version 9.26 and earlier does not properly check the size data of incomming write operations which an attacker can use to overflow memory buffers, resulting in a bug check and potentially arbitrary code execution in kernel space

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-1305"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-07-08T18:15:07Z",
    "severity": "CRITICAL"
  },
  "details": "tap-windows6 driver version 9.26 and earlier does not properly \ncheck the size data of incomming write operations which an attacker can \nuse to overflow memory buffers, resulting in a bug check and potentially\n arbitrary code execution in kernel space",
  "id": "GHSA-fv4p-hrvc-c34g",
  "modified": "2024-07-09T18:30:43Z",
  "published": "2024-07-08T18:31:18Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-1305"
    },
    {
      "type": "WEB",
      "url": "https://community.openvpn.net/openvpn/wiki/CVE-2024-1305"
    },
    {
      "type": "WEB",
      "url": "https://www.mail-archive.com/openvpn-users@lists.sourceforge.net/msg07534.html"
    }
  ],
  "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-FW8F-W2G8-Q74W

Vulnerability from github – Published: 2022-05-24 19:04 – Updated: 2022-05-24 19:04
VLAI
Details

In memory management driver, there is a possible out of bounds write due to an integer overflow. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android SoCAndroid ID: A-183461318

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2021-0494"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-06-11T17:15:00Z",
    "severity": "HIGH"
  },
  "details": "In memory management driver, there is a possible out of bounds write due to an integer overflow. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android SoCAndroid ID: A-183461318",
  "id": "GHSA-fw8f-w2g8-q74w",
  "modified": "2022-05-24T19:04:58Z",
  "published": "2022-05-24T19:04:58Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-0494"
    },
    {
      "type": "WEB",
      "url": "https://source.android.com/security/bulletin/2021-05-01"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

GHSA-FWRJ-5C8F-F8H2

Vulnerability from github – Published: 2023-12-13 09:30 – Updated: 2025-08-04 21:30
VLAI
Details

A flaw was found in xorg-server. A specially crafted request to RRChangeProviderProperty or RRChangeOutputProperty can trigger an integer overflow which may lead to a disclosure of sensitive information.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2023-6478"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-125",
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-12-13T07:15:31Z",
    "severity": "HIGH"
  },
  "details": "A flaw was found in xorg-server. A specially crafted request to RRChangeProviderProperty or RRChangeOutputProperty can trigger an integer overflow which may lead to a disclosure of sensitive information.",
  "id": "GHSA-fwrj-5c8f-f8h2",
  "modified": "2025-08-04T21:30:36Z",
  "published": "2023-12-13T09:30:32Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-6478"
    },
    {
      "type": "WEB",
      "url": "https://www.debian.org/security/2023/dsa-5576"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20240125-0003"
    },
    {
      "type": "WEB",
      "url": "https://security.gentoo.org/glsa/202401-30"
    },
    {
      "type": "WEB",
      "url": "https://lists.x.org/archives/xorg-announce/2023-December/003435.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LJDFWDB7EQVZA45XDP7L5WRSRWS6RVRR"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IFHV5KCQ2SVOD4QMCPZ5HC6YL44L7YJD"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7PP47YXKM5ETLCYEF6473R3VFCJ6QT2S"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6R63Z6GIWM3YUNZRCGFODUXLW3GY2HD6"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2023/12/msg00008.html"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.freedesktop.org/xorg/xserver/-/commit/14f480010a93ff962fef66a16412fafff81ad632"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2253298"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2023-6478"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2025:12751"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:2996"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:2995"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:2170"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:2169"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:0020"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:0018"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:0017"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:0016"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:0015"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:0014"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:0010"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:0009"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2024:0006"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2023:7886"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2023/12/13/1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-FX8P-5V6X-XJJV

Vulnerability from github – Published: 2022-05-14 02:05 – Updated: 2022-05-14 02:05
VLAI
Details

Integer overflow in inc/server.hpp in libnet6 (aka net6) before 1.3.14 might allow remote attackers to hijack connections and gain privileges as other users by making a large number of connections until the overflow occurs and an ID of another user is provided.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2011-4093"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2014-02-10T18:15:00Z",
    "severity": "MODERATE"
  },
  "details": "Integer overflow in inc/server.hpp in libnet6 (aka net6) before 1.3.14 might allow remote attackers to hijack connections and gain privileges as other users by making a large number of connections until the overflow occurs and an ID of another user is provided.",
  "id": "GHSA-fx8p-5v6x-xjjv",
  "modified": "2022-05-14T02:05:09Z",
  "published": "2022-05-14T02:05:09Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2011-4093"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.novell.com/show_bug.cgi?id=727710"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=750631"
    },
    {
      "type": "WEB",
      "url": "http://git.0x539.de/?p=net6.git%3Ba=commitdiff%3Bh=ac61d7fb42a1f977fb527e024bede319c4a9e169%3Bhp=08c8e2261604c6fcbbaf62f9ae9d13f7015fcb9a"
    },
    {
      "type": "WEB",
      "url": "http://git.0x539.de/?p=net6.git;a=commitdiff;h=ac61d7fb42a1f977fb527e024bede319c4a9e169;hp=08c8e2261604c6fcbbaf62f9ae9d13f7015fcb9a"
    },
    {
      "type": "WEB",
      "url": "http://lists.opensuse.org/opensuse-updates/2012-01/msg00044.html"
    },
    {
      "type": "WEB",
      "url": "http://lists.opensuse.org/opensuse-updates/2012-01/msg00054.html"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2011/10/31/1"
    },
    {
      "type": "WEB",
      "url": "http://www.oracle.com/technetwork/topics/security/bulletinapr2015-2511959.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

GHSA-FXC3-452X-46R5

Vulnerability from github – Published: 2022-05-13 01:07 – Updated: 2025-04-12 13:07
VLAI
Details

Integer overflow in the net_tx_pkt_init function in hw/net/net_tx_pkt.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (QEMU process crash) via the maximum fragmentation count, which triggers an unchecked multiplication and NULL pointer dereference.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2016-6888"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2016-12-10T00:59:00Z",
    "severity": "MODERATE"
  },
  "details": "Integer overflow in the net_tx_pkt_init function in hw/net/net_tx_pkt.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (QEMU process crash) via the maximum fragmentation count, which triggers an unchecked multiplication and NULL pointer dereference.",
  "id": "GHSA-fxc3-452x-46r5",
  "modified": "2025-04-12T13:07:01Z",
  "published": "2022-05-13T01:07:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2016-6888"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2017:2392"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2017:2408"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2018/11/msg00038.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.gnu.org/archive/html/qemu-devel/2016-08/msg03176.html"
    },
    {
      "type": "WEB",
      "url": "https://security.gentoo.org/glsa/201609-01"
    },
    {
      "type": "WEB",
      "url": "http://git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=47882fa4975bf0b58dd74474329fdd7154e8f04c"
    },
    {
      "type": "WEB",
      "url": "http://git.qemu.org/?p=qemu.git;a=commit;h=47882fa4975bf0b58dd74474329fdd7154e8f04c"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2016/08/19/10"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2016/08/19/6"
    },
    {
      "type": "WEB",
      "url": "http://www.securityfocus.com/bid/92556"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-FXF6-RPHP-PRHW

Vulnerability from github – Published: 2024-02-15 15:30 – Updated: 2024-02-15 18:30
VLAI
Details

Acrobat Reader versions 20.005.30539, 23.008.20470 and earlier are affected by an Integer Overflow or Wraparound vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-20730"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-02-15T13:15:47Z",
    "severity": "HIGH"
  },
  "details": "Acrobat Reader versions 20.005.30539, 23.008.20470 and earlier are affected by an Integer Overflow or Wraparound vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.",
  "id": "GHSA-fxf6-rphp-prhw",
  "modified": "2024-02-15T18:30:41Z",
  "published": "2024-02-15T15:30:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-20730"
    },
    {
      "type": "WEB",
      "url": "https://helpx.adobe.com/security/products/acrobat/apsb24-07.html"
    },
    {
      "type": "WEB",
      "url": "https://www.talosintelligence.com/vulnerability_reports/TALOS-2023-1906"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-FXGC-GQXW-X5RM

Vulnerability from github – Published: 2022-05-13 01:30 – Updated: 2022-05-13 01:30
VLAI
Details

An integer overflow vulnerability exists in the function multipleTransfer of Neo Genesis Token (NGT), an Ethereum token smart contract. An attacker could use it to set any user's balance.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2018-14006"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2018-07-12T15:29:00Z",
    "severity": "HIGH"
  },
  "details": "An integer overflow vulnerability exists in the function multipleTransfer of Neo Genesis Token (NGT), an Ethereum token smart contract. An attacker could use it to set any user\u0027s balance.",
  "id": "GHSA-fxgc-gqxw-x5rm",
  "modified": "2022-05-13T01:30:27Z",
  "published": "2022-05-13T01:30:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-14006"
    },
    {
      "type": "WEB",
      "url": "https://github.com/VenusADLab/EtherTokens/blob/master/SHARKTECH/SHARKTECH.md"
    },
    {
      "type": "WEB",
      "url": "https://github.com/VenusADLab/EtherTokens/tree/master/Neo%20Genesis%20Token(NGT)"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-FXGP-4MCH-4C5H

Vulnerability from github – Published: 2026-06-04 12:30 – Updated: 2026-06-04 12:30
VLAI
Details

Integer overflow or wraparound vulnerability in Samsung Open Source rlottie allows Integer Attacks.

This issue affects rlottie: before 21292665023e5074b38254432716866d00f1985f.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-49510"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-04T10:16:39Z",
    "severity": "MODERATE"
  },
  "details": "Integer overflow or wraparound vulnerability in Samsung Open Source rlottie allows Integer Attacks.\n\nThis issue affects rlottie:\u00a0before\u00a021292665023e5074b38254432716866d00f1985f.",
  "id": "GHSA-fxgp-4mch-4c5h",
  "modified": "2026-06-04T12:30:25Z",
  "published": "2026-06-04T12:30:25Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49510"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Samsung/rlottie/pull/592"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-FXPR-9FMX-9MGX

Vulnerability from github – Published: 2024-05-14 18:31 – Updated: 2024-05-14 18:31
VLAI
Details

Windows Mobile Broadband Driver Remote Code Execution Vulnerability

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-30012"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-05-14T17:16:43Z",
    "severity": "MODERATE"
  },
  "details": "Windows Mobile Broadband Driver Remote Code Execution Vulnerability",
  "id": "GHSA-fxpr-9fmx-9mgx",
  "modified": "2024-05-14T18:31:03Z",
  "published": "2024-05-14T18:31:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-30012"
    },
    {
      "type": "WEB",
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-30012"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

Mitigation
Requirements

Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.

Mitigation MIT-3
Requirements

Strategy: Language Selection

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
  • If possible, choose a language or compiler that performs automatic bounds checking.
Mitigation MIT-4
Architecture and Design

Strategy: Libraries or Frameworks

  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
  • Use libraries or frameworks that make it easier to handle numbers without unexpected consequences.
  • Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++). [REF-106]
Mitigation MIT-8
Implementation

Strategy: Input Validation

  • Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
  • Use unsigned integers where possible. This makes it easier to perform validation for integer overflows. When signed integers are required, ensure that the range check includes minimum values as well as maximum values.
Mitigation MIT-36
Implementation
  • Understand the programming language's underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, "not-a-number" calculations, and how the language handles numbers that are too large or too small for its underlying representation. [REF-7]
  • Also be careful to account for 32-bit, 64-bit, and other potential differences that may affect the numeric representation.
Mitigation MIT-15
Architecture and Design

For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

Mitigation MIT-26
Implementation

Strategy: Compilation or Build Hardening

Examine compiler warnings closely and eliminate problems with potential security implications, such as signed / unsigned mismatch in memory operations, or use of uninitialized variables. Even if the weakness is rarely exploitable, a single failure may lead to the compromise of the entire system.

CAPEC-92: Forced Integer Overflow

This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code.