CWE-367
AllowedTime-of-check Time-of-use (TOCTOU) Race Condition
Abstraction: Base · Status: Incomplete
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
1063 vulnerabilities reference this CWE, most recent first.
GHSA-P484-7M3W-W9XH
Vulnerability from github – Published: 2023-12-16 03:30 – Updated: 2023-12-20 18:30TOCTOU race-condition vulnerability in Insyde InsydeH2O with Kernel 5.2 before version 05.27.29, Kernel 5.3 before version 05.36.29, Kernel 5.4 version before 05.44.13, and Kernel 5.5 before version 05.52.13 allows an attacker to alter data and code used by the remainder of the boot process.
{
"affected": [],
"aliases": [
"CVE-2022-24351"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-12-16T02:15:07Z",
"severity": "MODERATE"
},
"details": "TOCTOU race-condition vulnerability in Insyde InsydeH2O with Kernel 5.2 before version 05.27.29, Kernel 5.3 before version 05.36.29, Kernel 5.4 version before 05.44.13, and Kernel 5.5 before version 05.52.13 allows an attacker to alter data and code used by the remainder of the boot process.",
"id": "GHSA-p484-7m3w-w9xh",
"modified": "2023-12-20T18:30:32Z",
"published": "2023-12-16T03:30:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-24351"
},
{
"type": "WEB",
"url": "https://www.insyde.com/security-pledge"
},
{
"type": "WEB",
"url": "https://www.insyde.com/security-pledge/SA-2023038"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-P64J-WWMG-JCP6
Vulnerability from github – Published: 2022-11-15 12:00 – Updated: 2022-11-18 18:30DMA transactions which are targeted at input buffers used for the AhciBusDxe software SMI handler could cause SMRAM corruption (a TOCTOU attack). DMA transactions which are targeted at input buffers used for the software SMI handler used by the AhciBusDxe driver could cause SMRAM corruption through a TOCTOU attack. This issue was discovered by Insyde engineering based on the general description provided by Intel's iSTARE group, Fixed in kernel 5.2: 05.27.23, kernel 5.3: 05.36.23, kernel 5.4: 05.44.23, kernel 5.5: 05.52.23 https://www.insyde.com/security-pledge/SA-2022047
{
"affected": [],
"aliases": [
"CVE-2022-33905"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-11-15T00:15:00Z",
"severity": "HIGH"
},
"details": "DMA transactions which are targeted at input buffers used for the AhciBusDxe software SMI handler could cause SMRAM corruption (a TOCTOU attack). DMA transactions which are targeted at input buffers used for the software SMI handler used by the AhciBusDxe driver could cause SMRAM corruption through a TOCTOU attack. This issue was discovered by Insyde engineering based on the general description provided by Intel\u0027s iSTARE group, Fixed in kernel 5.2: 05.27.23, kernel 5.3: 05.36.23, kernel 5.4: 05.44.23, kernel 5.5: 05.52.23 https://www.insyde.com/security-pledge/SA-2022047",
"id": "GHSA-p64j-wwmg-jcp6",
"modified": "2022-11-18T18:30:25Z",
"published": "2022-11-15T12:00:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-33905"
},
{
"type": "WEB",
"url": "https://www.insyde.com/security-pledge"
},
{
"type": "WEB",
"url": "https://www.insyde.com/security-pledge/SA-2022047"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-P7R9-XPGQ-6HGJ
Vulnerability from github – Published: 2024-04-30 18:30 – Updated: 2026-03-02 21:31Anti-tampering protection of the Zscaler Client Connector can be bypassed under certain conditions when running the Repair App functionality. This affects Zscaler Client Connector on Windows prior to 4.2.1
{
"affected": [],
"aliases": [
"CVE-2024-23463"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-04-30T17:15:46Z",
"severity": "HIGH"
},
"details": "Anti-tampering protection of the Zscaler Client Connector can be bypassed under certain conditions when running the Repair App functionality. This affects Zscaler Client Connector on Windows prior to 4.2.1",
"id": "GHSA-p7r9-xpgq-6hgj",
"modified": "2026-03-02T21:31:19Z",
"published": "2024-04-30T18:30:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-23463"
},
{
"type": "WEB",
"url": "https://help.zscaler.com/client-connector/client-connector-app-release-summary-2023"
}
],
"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:H",
"type": "CVSS_V3"
}
]
}
GHSA-P7XV-94HW-XX6P
Vulnerability from github – Published: 2022-05-24 17:44 – Updated: 2022-05-24 17:44While processing storage SCM commands there is a time of check or time of use window where a pointer used could be invalid at a specific time while executing the storage SCM call in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Wired Infrastructure and Networking
{
"affected": [],
"aliases": [
"CVE-2020-11220"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-03-17T06:15:00Z",
"severity": "MODERATE"
},
"details": "While processing storage SCM commands there is a time of check or time of use window where a pointer used could be invalid at a specific time while executing the storage SCM call in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Industrial IOT, Snapdragon Mobile, Snapdragon Wired Infrastructure and Networking",
"id": "GHSA-p7xv-94hw-xx6p",
"modified": "2022-05-24T17:44:41Z",
"published": "2022-05-24T17:44:41Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-11220"
},
{
"type": "WEB",
"url": "https://www.qualcomm.com/company/product-security/bulletins/march-2021-bulletin"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-P867-FXFR-PH2W
Vulnerability from github – Published: 2022-02-24 12:08 – Updated: 2024-09-04 20:56Impact
Linux and Mac releases of the SDK version 1.14.0 and below contain a key disclosure vulnerability that, in certain conditions, can be exploited by local attackers through a time-of-check-time-of-use (TOCTOU) race condition.
SDK users of the SqliteAccountInfo format are vulnerable while users of the InMemoryAccountInfo format are safe. The SqliteAccountInfo saves API keys (and bucket name-to-id mapping) in a local database file ($XDG_CONFIG_HOME/b2/account_info, ~/.b2_account_info or a user-defined path). When first created, the file is world readable and is (typically a few milliseconds) later altered to be private to the user. If the directory containing the file is readable by a local attacker then during the brief period between file creation and permission modification, a local attacker can race to open the file and maintain a handle to it. This allows the local attacker to read the contents after the file after the sensitive information has been saved to it.
Consumers of this SDK who rely on it to save data using SqliteAccountInfo class should upgrade to the latest version of the SDK. Those who believe a local user might have opened a handle using this race condition, should remove the affected database files and regenerate all application keys.
Patches
Users should upgrade to b2-sdk-python 1.14.1 or later.
For more information
See the related advisory in the B2 Command Line Tool, a consumer of this SDK.
If you have any questions or comments about this advisory: * Open an issue in b2-sdk-python * Email us at security@backblaze.com
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "b2sdk"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.14.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-23651"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": true,
"github_reviewed_at": "2022-02-24T12:08:24Z",
"nvd_published_at": "2022-02-23T23:15:00Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nLinux and Mac releases of the SDK version 1.14.0 and below contain a key disclosure vulnerability that, in certain conditions, can be exploited by local attackers through a time-of-check-time-of-use (TOCTOU) race condition.\n\nSDK users of the `SqliteAccountInfo` format are vulnerable while users of the `InMemoryAccountInfo` format are safe. The `SqliteAccountInfo` saves API keys (and bucket name-to-id mapping) in a local database file (`$XDG_CONFIG_HOME/b2/account_info`, `~/.b2_account_info` or a user-defined path). When first created, the file is world readable and is (typically a few milliseconds) later altered to be private to the user. If the directory containing the file is readable by a local attacker then during the brief period between file creation and permission modification, a local attacker can race to open the file and maintain a handle to it. This allows the local attacker to read the contents after the file after the sensitive information has been saved to it.\n\nConsumers of this SDK who rely on it to save data using `SqliteAccountInfo` class should upgrade to the latest version of the SDK. Those who believe a local user might have opened a handle using this race condition, should remove the affected database files and regenerate all application keys.\n\n### Patches\nUsers should upgrade to b2-sdk-python 1.14.1 or later.\n\n### For more information\nSee the related advisory in the [B2 Command Line Tool](https://github.com/Backblaze/B2_Command_Line_Tool), a consumer of this SDK.\n\nIf you have any questions or comments about this advisory:\n* Open an issue in [b2-sdk-python](https://github.com/Backblaze/b2-sdk-python)\n* Email us at [security@backblaze.com](mailto:security@backblaze.com)\n",
"id": "GHSA-p867-fxfr-ph2w",
"modified": "2024-09-04T20:56:19Z",
"published": "2022-02-24T12:08:24Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/Backblaze/b2-sdk-python/security/advisories/GHSA-p867-fxfr-ph2w"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-23651"
},
{
"type": "WEB",
"url": "https://github.com/Backblaze/b2-sdk-python/commit/62476638986e5b6d7459aca5ef8ce220760226e0"
},
{
"type": "PACKAGE",
"url": "https://github.com/Backblaze/b2-sdk-python"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/b2sdk/PYSEC-2022-33.yaml"
},
{
"type": "WEB",
"url": "https://pypi.org/project/b2sdk"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "b2-sdk-python TOCTOU application key disclosure "
}
GHSA-P8VR-M38H-GW25
Vulnerability from github – Published: 2025-08-06 03:30 – Updated: 2025-08-06 03:30Race condition vulnerability in the virtualization base module. Successful exploitation of this vulnerability may affect the confidentiality and integrity of the virtualization graphics module.
{
"affected": [],
"aliases": [
"CVE-2025-54655"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-08-06T01:15:26Z",
"severity": "HIGH"
},
"details": "Race condition vulnerability in the virtualization base module. Successful exploitation of this vulnerability may affect the confidentiality and integrity of the virtualization graphics module.",
"id": "GHSA-p8vr-m38h-gw25",
"modified": "2025-08-06T03:30:23Z",
"published": "2025-08-06T03:30:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-54655"
},
{
"type": "WEB",
"url": "https://consumer.huawei.com/cn/support/bulletinlaptops/2025/8"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-P9F7-MWQH-HWRJ
Vulnerability from github – Published: 2025-04-07 12:33 – Updated: 2025-04-07 12:33Information disclosure may be there when a guest VM is connected.
{
"affected": [],
"aliases": [
"CVE-2025-21431"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-04-07T11:15:51Z",
"severity": "MODERATE"
},
"details": "Information disclosure may be there when a guest VM is connected.",
"id": "GHSA-p9f7-mwqh-hwrj",
"modified": "2025-04-07T12:33:18Z",
"published": "2025-04-07T12:33:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-21431"
},
{
"type": "WEB",
"url": "https://docs.qualcomm.com/product/publicresources/securitybulletin/april-2025-bulletin.html"
}
],
"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-PC33-GMP7-WV52
Vulnerability from github – Published: 2026-02-11 15:30 – Updated: 2026-03-05 18:31A Time-of-check time-of-use (TOCTOU) race condition in the AMD Secure Processor (ASP) could allow an attacker to corrupt memory resulting in loss of integrity, confidentiality, or availability.
{
"affected": [],
"aliases": [
"CVE-2023-20548"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-02-11T15:16:11Z",
"severity": "HIGH"
},
"details": "A Time-of-check time-of-use (TOCTOU) race condition in the AMD Secure Processor (ASP) could allow an attacker to corrupt memory resulting in loss of integrity, confidentiality, or availability.",
"id": "GHSA-pc33-gmp7-wv52",
"modified": "2026-03-05T18:31:34Z",
"published": "2026-02-11T15:30:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-20548"
},
{
"type": "WEB",
"url": "https://www.amd.com/en/resources/product-security/bulletin/AMD-SB-6024.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:L/VI:H/VA:L/SC:L/SI:H/SA:L/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-PF35-CH3J-QPG8
Vulnerability from github – Published: 2022-05-13 01:53 – Updated: 2022-05-13 01:53A security feature bypass exists when Device Guard incorrectly validates an untrusted file, aka "Device Guard Security Feature Bypass Vulnerability." This affects Windows Server 2016, Windows 10, Windows 10 Servers.
{
"affected": [],
"aliases": [
"CVE-2018-8449"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-09-13T00:29:00Z",
"severity": "LOW"
},
"details": "A security feature bypass exists when Device Guard incorrectly validates an untrusted file, aka \"Device Guard Security Feature Bypass Vulnerability.\" This affects Windows Server 2016, Windows 10, Windows 10 Servers.",
"id": "GHSA-pf35-ch3j-qpg8",
"modified": "2022-05-13T01:53:42Z",
"published": "2022-05-13T01:53:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-8449"
},
{
"type": "WEB",
"url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8449"
},
{
"type": "WEB",
"url": "https://www.exploit-db.com/exploits/45435"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/105272"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id/1041642"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-PF4V-7Q2J-5RW9
Vulnerability from github – Published: 2025-09-05 18:31 – Updated: 2026-05-12 15:31In the Linux kernel, the following vulnerability has been resolved:
media: rainshadow-cec: fix TOCTOU race condition in rain_interrupt()
In the interrupt handler rain_interrupt(), the buffer full check on rain->buf_len is performed before acquiring rain->buf_lock. This creates a Time-of-Check to Time-of-Use (TOCTOU) race condition, as rain->buf_len is concurrently accessed and modified in the work handler rain_irq_work_handler() under the same lock.
Multiple interrupt invocations can race, with each reading buf_len before it becomes full and then proceeding. This can lead to both interrupts attempting to write to the buffer, incrementing buf_len beyond its capacity (DATA_SIZE) and causing a buffer overflow.
Fix this bug by moving the spin_lock() to before the buffer full check. This ensures that the check and the subsequent buffer modification are performed atomically, preventing the race condition. An corresponding spin_unlock() is added to the overflow path to correctly release the lock.
This possible bug was found by an experimental static analysis tool developed by our team.
{
"affected": [],
"aliases": [
"CVE-2025-39713"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-09-05T18:15:48Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: rainshadow-cec: fix TOCTOU race condition in rain_interrupt()\n\nIn the interrupt handler rain_interrupt(), the buffer full check on\nrain-\u003ebuf_len is performed before acquiring rain-\u003ebuf_lock. This\ncreates a Time-of-Check to Time-of-Use (TOCTOU) race condition, as\nrain-\u003ebuf_len is concurrently accessed and modified in the work\nhandler rain_irq_work_handler() under the same lock.\n\nMultiple interrupt invocations can race, with each reading buf_len\nbefore it becomes full and then proceeding. This can lead to both\ninterrupts attempting to write to the buffer, incrementing buf_len\nbeyond its capacity (DATA_SIZE) and causing a buffer overflow.\n\nFix this bug by moving the spin_lock() to before the buffer full\ncheck. This ensures that the check and the subsequent buffer modification\nare performed atomically, preventing the race condition. An corresponding\nspin_unlock() is added to the overflow path to correctly release the\nlock.\n\nThis possible bug was found by an experimental static analysis tool\ndeveloped by our team.",
"id": "GHSA-pf4v-7q2j-5rw9",
"modified": "2026-05-12T15:31:04Z",
"published": "2025-09-05T18:31:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-39713"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-032379.html"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1c2769dc80255824542ea5a4ff1a07dcdeb1603f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2964dbe631fd21ad7873b1752b895548d3c12496"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3c3e33b7edca7a2d6a96801f287f9faeb684d655"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6aaef1a75985865d8c6c5b65fb54152060faba48"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7af160aea26c7dc9e6734d19306128cce156ec40"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ed905fe7cba03cf22ae0b84cf1b73cd1c070423a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fbc81e78d75bf28972bc22b1599559557b1a1b83"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ff9dd3db6cd4c6b54a2ecbc58151bea4ec63bc59"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Mitigation
The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
Mitigation
When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
Mitigation
Limit the interleaving of operations on files from multiple processes.
Mitigation
If you cannot perform operations atomically and you must share access to the resource between multiple processes or threads, then try to limit the amount of time (CPU cycles) between the check and use of the resource. This will not fix the problem, but it could make it more difficult for an attack to succeed.
Mitigation
Recheck the resource after the use call to verify that the action was taken appropriately.
Mitigation
Ensure that some environmental locking mechanism can be used to protect resources effectively.
Mitigation
Ensure that locking occurs before the check, as opposed to afterwards, such that the resource, as checked, is the same as it is when in use.
CAPEC-27: Leveraging Race Conditions via Symbolic Links
This attack leverages the use of symbolic links (Symlinks) in order to write to sensitive files. An attacker can create a Symlink link to a target file not otherwise accessible to them. When the privileged program tries to create a temporary file with the same name as the Symlink link, it will actually write to the target file pointed to by the attackers' Symlink link. If the attacker can insert malicious content in the temporary file they will be writing to the sensitive file by using the Symlink. The race occurs because the system checks if the temporary file exists, then creates the file. The attacker would typically create the Symlink during the interval between the check and the creation of the temporary file.
CAPEC-29: Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. A typical example is file access. The adversary can leverage a file access race condition by "running the race", meaning that they would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the adversary could replace or modify the file, causing the application to behave unexpectedly.