Common Weakness Enumeration
CWE-59
AllowedImproper Link Resolution Before File Access ('Link Following')
Abstraction: Base · Status: Draft
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
2063 vulnerabilities reference this CWE, most recent first.
GHSA-W845-647Q-RR58
Vulnerability from github – Published: 2022-05-17 02:18 – Updated: 2022-05-17 02:18
VLAI
Details
The (1) ncsarmt and (2) ncsawrap scripts in xmcd 2.6 allows local users to overwrite arbitrary files via a symlink attack on a /tmp/Mosaic.*pid temporary file.
{
"affected": [],
"aliases": [
"CVE-2008-4994"
],
"database_specific": {
"cwe_ids": [
"CWE-59"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2008-11-07T19:36:00Z",
"severity": "MODERATE"
},
"details": "The (1) ncsarmt and (2) ncsawrap scripts in xmcd 2.6 allows local users to overwrite arbitrary files via a symlink attack on a /tmp/Mosaic.*pid temporary file.",
"id": "GHSA-w845-647q-rr58",
"modified": "2022-05-17T02:18:26Z",
"published": "2022-05-17T02:18:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-4994"
},
{
"type": "WEB",
"url": "https://bugs.gentoo.org/show_bug.cgi?id=235770"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/46550"
},
{
"type": "WEB",
"url": "http://bugs.debian.org/496416"
},
{
"type": "WEB",
"url": "http://dev.gentoo.org/~rbu/security/debiantemp/xmcd"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2008/10/30/2"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/32288"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-W853-JP5J-5J7F
Vulnerability from github – Published: 2025-12-16 20:52 – Updated: 2025-12-16 20:52
VLAI
Summary
filelock has a TOCTOU race condition which allows symlink attacks during lock file creation
Details
Impact
A Time-of-Check-Time-of-Use (TOCTOU) race condition allows local attackers to corrupt or truncate arbitrary user files through symlink attacks. The vulnerability exists in both Unix and Windows lock file creation where filelock checks if a file exists before opening it with O_TRUNC. An attacker can create a symlink pointing to a victim file in the time gap between the check and open, causing os.open() to follow the symlink and truncate the target file.
Who is impacted:
All users of filelock on Unix, Linux, macOS, and Windows systems. The vulnerability cascades to dependent libraries:
- virtualenv users: Configuration files can be overwritten with virtualenv metadata, leaking sensitive paths
- PyTorch users: CPU ISA cache or model checkpoints can be corrupted, causing crashes or ML pipeline failures
- poetry/tox users: through using virtualenv or filelock on their own.
Attack requires local filesystem access and ability to create symlinks (standard user permissions on Unix; Developer Mode on Windows 10+). Exploitation succeeds within 1-3 attempts when lock file paths are predictable.
Patches
Fixed in version 3.20.1.
Unix/Linux/macOS fix: Added O_NOFOLLOW flag to os.open() in UnixFileLock._acquire() to prevent symlink following.
Windows fix: Added GetFileAttributesW API check to detect reparse points (symlinks/junctions) before opening files in WindowsFileLock._acquire().
Users should upgrade to filelock 3.20.1 or later immediately.
Workarounds
If immediate upgrade is not possible:
- Use SoftFileLock instead of UnixFileLock/WindowsFileLock (note: different locking semantics, may not be suitable for all use cases)
- Ensure lock file directories have restrictive permissions (chmod 0700) to prevent untrusted users from creating symlinks
- Monitor lock file directories for suspicious symlinks before running trusted applications
Warning: These workarounds provide only partial mitigation. The race condition remains exploitable. Upgrading to version 3.20.1 is strongly recommended.
Technical Details: How the Exploit Works
The Vulnerable Code Pattern
Unix/Linux/macOS (src/filelock/_unix.py:39-44):
def _acquire(self) -> None:
ensure_directory_exists(self.lock_file)
open_flags = os.O_RDWR | os.O_TRUNC # (1) Prepare to truncate
if not Path(self.lock_file).exists(): # (2) CHECK: Does file exist?
open_flags |= os.O_CREAT
fd = os.open(self.lock_file, open_flags, ...) # (3) USE: Open and truncate
Windows (src/filelock/_windows.py:19-28):
def _acquire(self) -> None:
raise_on_not_writable_file(self.lock_file) # (1) Check writability
ensure_directory_exists(self.lock_file)
flags = os.O_RDWR | os.O_CREAT | os.O_TRUNC # (2) Prepare to truncate
fd = os.open(self.lock_file, flags, ...) # (3) Open and truncate
The Race Window
The vulnerability exists in the gap between operations:
Unix variant:
Time Victim Thread Attacker Thread
---- ------------- ---------------
T0 Check: lock_file exists? → False
T1 ↓ RACE WINDOW
T2 Create symlink: lock → victim_file
T3 Open lock_file with O_TRUNC
→ Follows symlink
→ Opens victim_file
→ Truncates victim_file to 0 bytes! ☠️
Windows variant:
Time Victim Thread Attacker Thread
---- ------------- ---------------
T0 Check: lock_file writable?
T1 ↓ RACE WINDOW
T2 Create symlink: lock → victim_file
T3 Open lock_file with O_TRUNC
→ Follows symlink/junction
→ Opens victim_file
→ Truncates victim_file to 0 bytes! ☠️
Step-by-Step Attack Flow
1. Attacker Setup:
# Attacker identifies target application using filelock
lock_path = "/tmp/myapp.lock" # Predictable lock path
victim_file = "/home/victim/.ssh/config" # High-value target
2. Attacker Creates Race Condition:
import os
import threading
def attacker_thread():
# Remove any existing lock file
try:
os.unlink(lock_path)
except FileNotFoundError:
pass
# Create symlink pointing to victim file
os.symlink(victim_file, lock_path)
print(f"[Attacker] Created: {lock_path} → {victim_file}")
# Launch attack
threading.Thread(target=attacker_thread).start()
3. Victim Application Runs:
from filelock import UnixFileLock
# Normal application code
lock = UnixFileLock("/tmp/myapp.lock")
lock.acquire() # ← VULNERABILITY TRIGGERED HERE
# At this point, /home/victim/.ssh/config is now 0 bytes!
4. What Happens Inside os.open():
On Unix systems, when os.open() is called:
// Linux kernel behavior (simplified)
int open(const char *pathname, int flags) {
struct file *f = path_lookup(pathname); // Resolves symlinks by default!
if (flags & O_TRUNC) {
truncate_file(f); // ← Truncates the TARGET of the symlink
}
return file_descriptor;
}
Without O_NOFOLLOW flag, the kernel follows the symlink and truncates the target file.
Why the Attack Succeeds Reliably
Timing Characteristics:
- Check operation (Path.exists()): ~100-500 nanoseconds
- Symlink creation (os.symlink()): ~1-10 microseconds
- Race window: ~1-5 microseconds (very small but exploitable)
- Thread scheduling quantum: ~1-10 milliseconds
Success factors:
- Tight loop: Running attack in a loop hits the race window within 1-3 attempts
- CPU scheduling: Modern OS thread schedulers frequently context-switch during I/O operations
- No synchronization: No atomic file creation prevents the race
- Symlink speed: Creating symlinks is extremely fast (metadata-only operation)
Real-World Attack Scenarios
Scenario 1: virtualenv Exploitation
# Victim runs: python -m venv /tmp/myenv
# Attacker racing to create:
os.symlink("/home/victim/.bashrc", "/tmp/myenv/pyvenv.cfg")
# Result: /home/victim/.bashrc overwritten with:
# home = /usr/bin/python3
# include-system-site-packages = false
# version = 3.11.2
# ← Original .bashrc contents LOST + virtualenv metadata LEAKED to attacker
Scenario 2: PyTorch Cache Poisoning
# Victim runs: import torch
# PyTorch checks CPU capabilities, uses filelock on cache
# Attacker racing to create:
os.symlink("/home/victim/.torch/compiled_model.pt", "/home/victim/.cache/torch/cpu_isa_check.lock")
# Result: Trained ML model checkpoint truncated to 0 bytes
# Impact: Weeks of training lost, ML pipeline DoS
Why Standard Defenses Don't Help
File permissions don't prevent this:
- Attacker doesn't need write access to victim_file
- os.open() with O_TRUNC follows symlinks using the victim's permissions
- The victim process truncates its own file
Directory permissions help but aren't always feasible:
- Lock files often created in shared /tmp directory (mode 1777)
- Applications may not control lock file location
- Many apps use predictable paths in user-writable directories
File locking doesn't prevent this:
- The truncation happens during the open() call, before any lock is acquired
- fcntl.flock() only prevents concurrent lock acquisition, not symlink attacks
Exploitation Proof-of-Concept Results
From empirical testing with the provided PoCs:
Simple Direct Attack (filelock_simple_poc.py):
- Success rate: 33% per attempt (1 in 3 tries)
- Average attempts to success: 2.1
- Target file reduced to 0 bytes in \<100ms
virtualenv Attack (weaponized_virtualenv.py):
- Success rate: ~90% on first attempt (deterministic timing)
- Information leaked: File paths, Python version, system configuration
- Data corruption: Complete loss of original file contents
PyTorch Attack (weaponized_pytorch.py):
- Success rate: 25-40% per attempt
- Impact: Application crashes, model loading failures
- Recovery: Requires cache rebuild or model retraining
Discovered and reported by: George Tsigourakos (@tsigouris007)
Severity
6.3 (Medium)
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "filelock"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.20.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-68146"
],
"database_specific": {
"cwe_ids": [
"CWE-362",
"CWE-367",
"CWE-59"
],
"github_reviewed": true,
"github_reviewed_at": "2025-12-16T20:52:55Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Impact\n\nA Time-of-Check-Time-of-Use (TOCTOU) race condition allows local attackers to corrupt or truncate arbitrary user files through symlink attacks. The vulnerability exists in both Unix and Windows lock file creation where filelock checks if a file exists before opening it with O_TRUNC. An attacker can create a symlink pointing to a victim file in the time gap between the check and open, causing os.open() to follow the symlink and truncate the target file.\n\n**Who is impacted:**\n\nAll users of filelock on Unix, Linux, macOS, and Windows systems. The vulnerability cascades to dependent libraries:\n\n- **virtualenv users**: Configuration files can be overwritten with virtualenv metadata, leaking sensitive paths\n- **PyTorch users**: CPU ISA cache or model checkpoints can be corrupted, causing crashes or ML pipeline failures\n- **poetry/tox users**: through using virtualenv or filelock on their own.\n\nAttack requires local filesystem access and ability to create symlinks (standard user permissions on Unix; Developer Mode on Windows 10+). Exploitation succeeds within 1-3 attempts when lock file paths are predictable.\n\n### Patches\n\nFixed in version **3.20.1**.\n\n**Unix/Linux/macOS fix:** Added O_NOFOLLOW flag to os.open() in UnixFileLock.\\_acquire() to prevent symlink following.\n\n**Windows fix:** Added GetFileAttributesW API check to detect reparse points (symlinks/junctions) before opening files in WindowsFileLock.\\_acquire().\n\n**Users should upgrade to filelock 3.20.1 or later immediately.**\n\n### Workarounds\n\nIf immediate upgrade is not possible:\n\n1. Use SoftFileLock instead of UnixFileLock/WindowsFileLock (note: different locking semantics, may not be suitable for all use cases)\n2. Ensure lock file directories have restrictive permissions (chmod 0700) to prevent untrusted users from creating symlinks\n3. Monitor lock file directories for suspicious symlinks before running trusted applications\n\n**Warning:** These workarounds provide only partial mitigation. The race condition remains exploitable. Upgrading to version 3.20.1 is strongly recommended.\n\n______________________________________________________________________\n\n## Technical Details: How the Exploit Works\n\n### The Vulnerable Code Pattern\n\n**Unix/Linux/macOS** (`src/filelock/_unix.py:39-44`):\n\n```python\ndef _acquire(self) -\u003e None:\n ensure_directory_exists(self.lock_file)\n open_flags = os.O_RDWR | os.O_TRUNC # (1) Prepare to truncate\n if not Path(self.lock_file).exists(): # (2) CHECK: Does file exist?\n open_flags |= os.O_CREAT\n fd = os.open(self.lock_file, open_flags, ...) # (3) USE: Open and truncate\n```\n\n**Windows** (`src/filelock/_windows.py:19-28`):\n\n```python\ndef _acquire(self) -\u003e None:\n raise_on_not_writable_file(self.lock_file) # (1) Check writability\n ensure_directory_exists(self.lock_file)\n flags = os.O_RDWR | os.O_CREAT | os.O_TRUNC # (2) Prepare to truncate\n fd = os.open(self.lock_file, flags, ...) # (3) Open and truncate\n```\n\n### The Race Window\n\nThe vulnerability exists in the gap between operations:\n\n**Unix variant:**\n\n```\nTime Victim Thread Attacker Thread\n---- ------------- ---------------\nT0 Check: lock_file exists? \u2192 False\nT1 \u2193 RACE WINDOW\nT2 Create symlink: lock \u2192 victim_file\nT3 Open lock_file with O_TRUNC\n \u2192 Follows symlink\n \u2192 Opens victim_file\n \u2192 Truncates victim_file to 0 bytes! \u2620\ufe0f\n```\n\n**Windows variant:**\n\n```\nTime Victim Thread Attacker Thread\n---- ------------- ---------------\nT0 Check: lock_file writable?\nT1 \u2193 RACE WINDOW\nT2 Create symlink: lock \u2192 victim_file\nT3 Open lock_file with O_TRUNC\n \u2192 Follows symlink/junction\n \u2192 Opens victim_file\n \u2192 Truncates victim_file to 0 bytes! \u2620\ufe0f\n```\n\n### Step-by-Step Attack Flow\n\n**1. Attacker Setup:**\n\n```python\n# Attacker identifies target application using filelock\nlock_path = \"/tmp/myapp.lock\" # Predictable lock path\nvictim_file = \"/home/victim/.ssh/config\" # High-value target\n```\n\n**2. Attacker Creates Race Condition:**\n\n```python\nimport os\nimport threading\n\n\ndef attacker_thread():\n # Remove any existing lock file\n try:\n os.unlink(lock_path)\n except FileNotFoundError:\n pass\n\n # Create symlink pointing to victim file\n os.symlink(victim_file, lock_path)\n print(f\"[Attacker] Created: {lock_path} \u2192 {victim_file}\")\n\n\n# Launch attack\nthreading.Thread(target=attacker_thread).start()\n```\n\n**3. Victim Application Runs:**\n\n```python\nfrom filelock import UnixFileLock\n\n# Normal application code\nlock = UnixFileLock(\"/tmp/myapp.lock\")\nlock.acquire() # \u2190 VULNERABILITY TRIGGERED HERE\n# At this point, /home/victim/.ssh/config is now 0 bytes!\n```\n\n**4. What Happens Inside os.open():**\n\nOn Unix systems, when `os.open()` is called:\n\n```c\n// Linux kernel behavior (simplified)\nint open(const char *pathname, int flags) {\n struct file *f = path_lookup(pathname); // Resolves symlinks by default!\n\n if (flags \u0026 O_TRUNC) {\n truncate_file(f); // \u2190 Truncates the TARGET of the symlink\n }\n\n return file_descriptor;\n}\n```\n\nWithout `O_NOFOLLOW` flag, the kernel follows the symlink and truncates the target file.\n\n### Why the Attack Succeeds Reliably\n\n**Timing Characteristics:**\n\n- **Check operation** (Path.exists()): ~100-500 nanoseconds\n- **Symlink creation** (os.symlink()): ~1-10 microseconds\n- **Race window**: ~1-5 microseconds (very small but exploitable)\n- **Thread scheduling quantum**: ~1-10 milliseconds\n\n**Success factors:**\n\n1. **Tight loop**: Running attack in a loop hits the race window within 1-3 attempts\n2. **CPU scheduling**: Modern OS thread schedulers frequently context-switch during I/O operations\n3. **No synchronization**: No atomic file creation prevents the race\n4. **Symlink speed**: Creating symlinks is extremely fast (metadata-only operation)\n\n### Real-World Attack Scenarios\n\n**Scenario 1: virtualenv Exploitation**\n\n```python\n# Victim runs: python -m venv /tmp/myenv\n# Attacker racing to create:\nos.symlink(\"/home/victim/.bashrc\", \"/tmp/myenv/pyvenv.cfg\")\n\n# Result: /home/victim/.bashrc overwritten with:\n# home = /usr/bin/python3\n# include-system-site-packages = false\n# version = 3.11.2\n# \u2190 Original .bashrc contents LOST + virtualenv metadata LEAKED to attacker\n```\n\n**Scenario 2: PyTorch Cache Poisoning**\n\n```python\n# Victim runs: import torch\n# PyTorch checks CPU capabilities, uses filelock on cache\n# Attacker racing to create:\nos.symlink(\"/home/victim/.torch/compiled_model.pt\", \"/home/victim/.cache/torch/cpu_isa_check.lock\")\n\n# Result: Trained ML model checkpoint truncated to 0 bytes\n# Impact: Weeks of training lost, ML pipeline DoS\n```\n\n### Why Standard Defenses Don\u0027t Help\n\n**File permissions don\u0027t prevent this:**\n\n- Attacker doesn\u0027t need write access to victim_file\n- os.open() with O_TRUNC follows symlinks using the *victim\u0027s* permissions\n- The victim process truncates its own file\n\n**Directory permissions help but aren\u0027t always feasible:**\n\n- Lock files often created in shared /tmp directory (mode 1777)\n- Applications may not control lock file location\n- Many apps use predictable paths in user-writable directories\n\n**File locking doesn\u0027t prevent this:**\n\n- The truncation happens *during* the open() call, before any lock is acquired\n- fcntl.flock() only prevents concurrent lock acquisition, not symlink attacks\n\n### Exploitation Proof-of-Concept Results\n\nFrom empirical testing with the provided PoCs:\n\n**Simple Direct Attack** (`filelock_simple_poc.py`):\n\n- Success rate: 33% per attempt (1 in 3 tries)\n- Average attempts to success: 2.1\n- Target file reduced to 0 bytes in \\\u003c100ms\n\n**virtualenv Attack** (`weaponized_virtualenv.py`):\n\n- Success rate: ~90% on first attempt (deterministic timing)\n- Information leaked: File paths, Python version, system configuration\n- Data corruption: Complete loss of original file contents\n\n**PyTorch Attack** (`weaponized_pytorch.py`):\n\n- Success rate: 25-40% per attempt\n- Impact: Application crashes, model loading failures\n- Recovery: Requires cache rebuild or model retraining\n\n**Discovered and reported by:** George Tsigourakos (@tsigouris007)",
"id": "GHSA-w853-jp5j-5j7f",
"modified": "2025-12-16T20:52:55Z",
"published": "2025-12-16T20:52:55Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/tox-dev/filelock/security/advisories/GHSA-w853-jp5j-5j7f"
},
{
"type": "WEB",
"url": "https://github.com/tox-dev/filelock/commit/4724d7f8c3393ec1f048c93933e6e3e6ec321f0e"
},
{
"type": "PACKAGE",
"url": "https://github.com/tox-dev/filelock"
},
{
"type": "WEB",
"url": "https://github.com/tox-dev/filelock/releases/tag/3.20.1"
},
{
"type": "WEB",
"url": "https://learn.microsoft.com/en-us/windows/win32/fileio/file-attribute-constants"
},
{
"type": "WEB",
"url": "https://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html"
}
],
"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:H",
"type": "CVSS_V3"
}
],
"summary": "filelock has a TOCTOU race condition which allows symlink attacks during lock file creation"
}
GHSA-W8G8-VHWR-GR27
Vulnerability from github – Published: 2024-01-15 15:30 – Updated: 2024-10-10 18:31
VLAI
Details
PAX Android based POS devices with PayDroid_8.1.0_Sagittarius_V11.1.50_20230614 or earlier can allow for command execution with high privileges by using malicious symlinks.
The attacker must have shell access to the device in order to exploit this vulnerability.
Severity
7.8 (High)
{
"affected": [],
"aliases": [
"CVE-2023-42137"
],
"database_specific": {
"cwe_ids": [
"CWE-20",
"CWE-59"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-01-15T14:15:24Z",
"severity": "HIGH"
},
"details": "PAX Android based POS devices with PayDroid_8.1.0_Sagittarius_V11.1.50_20230614 or earlier can allow for command execution with high privileges by using malicious symlinks.\n\n\n\n\nThe attacker must have shell access to the device in order to exploit this vulnerability. \n\n\n",
"id": "GHSA-w8g8-vhwr-gr27",
"modified": "2024-10-10T18:31:07Z",
"published": "2024-01-15T15:30:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-42137"
},
{
"type": "WEB",
"url": "https://blog.stmcyber.com/pax-pos-cves-2023"
},
{
"type": "WEB",
"url": "https://cert.pl/en/posts/2024/01/CVE-2023-4818"
},
{
"type": "WEB",
"url": "https://cert.pl/posts/2024/01/CVE-2023-4818"
},
{
"type": "WEB",
"url": "https://ppn.paxengine.com/release/development"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-W8P2-VHRJ-74P5
Vulnerability from github – Published: 2022-05-01 23:28 – Updated: 2022-05-01 23:28
VLAI
Details
The write_array_file function in utils/include.pl in GForge 4.5.14 updates configuration files by truncating them to zero length and then writing new data, which might allow attackers to bypass intended access restrictions or have unspecified other impact in opportunistic circumstances.
{
"affected": [],
"aliases": [
"CVE-2008-0167"
],
"database_specific": {
"cwe_ids": [
"CWE-59"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2008-05-18T14:20:00Z",
"severity": "MODERATE"
},
"details": "The write_array_file function in utils/include.pl in GForge 4.5.14 updates configuration files by truncating them to zero length and then writing new data, which might allow attackers to bypass intended access restrictions or have unspecified other impact in opportunistic circumstances.",
"id": "GHSA-w8p2-vhrj-74p5",
"modified": "2022-05-01T23:28:06Z",
"published": "2022-05-01T23:28:06Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-0167"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/42456"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/30088"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/30286"
},
{
"type": "WEB",
"url": "http://security.debian.org/pool/updates/main/g/gforge/gforge_4.5.14-22etch8.diff.gz"
},
{
"type": "WEB",
"url": "http://www.debian.org/security/2008/dsa-1577"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/29215"
},
{
"type": "WEB",
"url": "http://www.vupen.com/english/advisories/2008/1537/references"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-W8VQ-HJWG-7P95
Vulnerability from github – Published: 2022-05-13 01:11 – Updated: 2022-05-13 01:11
VLAI
Details
The PEAR_REST class in REST.php in PEAR in PHP through 5.6.0 allows local users to write to arbitrary files via a symlink attack on a (1) rest.cachefile or (2) rest.cacheid file in /tmp/pear/cache/, related to the retrieveCacheFirst and useLocalCache functions.
{
"affected": [],
"aliases": [
"CVE-2014-5459"
],
"database_specific": {
"cwe_ids": [
"CWE-59"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2014-09-27T10:55:00Z",
"severity": "LOW"
},
"details": "The PEAR_REST class in REST.php in PEAR in PHP through 5.6.0 allows local users to write to arbitrary files via a symlink attack on a (1) rest.cachefile or (2) rest.cacheid file in /tmp/pear/cache/, related to the retrieveCacheFirst and useLocalCache functions.",
"id": "GHSA-w8vq-hjwg-7p95",
"modified": "2022-05-13T01:11:18Z",
"published": "2022-05-13T01:11:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2014-5459"
},
{
"type": "WEB",
"url": "https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=759282"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-updates/2014-09/msg00024.html"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-updates/2014-09/msg00055.html"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2014/08/27/3"
},
{
"type": "WEB",
"url": "http://www.oracle.com/technetwork/topics/security/bulletinjan2015-2370101.html"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-W952-587W-J326
Vulnerability from github – Published: 2022-05-17 05:53 – Updated: 2022-05-17 05:53
VLAI
Details
** DISPUTED ** dfxml-invoice in datafreedom-perl 0.1.7 allows local users to overwrite arbitrary files via a symlink attack on the /tmp/zenity temporary file. NOTE: the vendor disputes this vulnerability, stating that the vector is solely "an EXAMPLE used in the manpage."
{
"affected": [],
"aliases": [
"CVE-2008-4997"
],
"database_specific": {
"cwe_ids": [
"CWE-59"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2008-11-07T19:36:00Z",
"severity": "MODERATE"
},
"details": "** DISPUTED ** dfxml-invoice in datafreedom-perl 0.1.7 allows local users to overwrite arbitrary files via a symlink attack on the /tmp/zenity temporary file. NOTE: the vendor disputes this vulnerability, stating that the vector is solely \"an EXAMPLE used in the manpage.\"",
"id": "GHSA-w952-587w-j326",
"modified": "2022-05-17T05:53:38Z",
"published": "2022-05-17T05:53:38Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-4997"
},
{
"type": "WEB",
"url": "https://bugs.gentoo.org/show_bug.cgi?id=235770"
},
{
"type": "WEB",
"url": "http://bugs.debian.org/496429"
},
{
"type": "WEB",
"url": "http://dev.gentoo.org/~rbu/security/debiantemp/datafreedom-perl"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2008/10/30/2"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-W9R7-4GWR-J959
Vulnerability from github – Published: 2026-07-14 00:31 – Updated: 2026-07-14 00:31
VLAI
Details
FlashAttention through 2.8.3.post1, fixed in commit 0816ef1, contains a symlink attack vulnerability in the download_and_copy() function within hopper/setup.py that extracts NVIDIA toolchain archives without validating symlinks or filtering tar members. A local attacker can pre-plant a symlink in the predictable cache directory to redirect extracted binaries to an attacker-chosen location, enabling arbitrary file write with victim privileges during build time.
Severity
6.6 (Medium)
{
"affected": [],
"aliases": [
"CVE-2026-62239"
],
"database_specific": {
"cwe_ids": [
"CWE-59"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-13T22:16:51Z",
"severity": "MODERATE"
},
"details": "FlashAttention through 2.8.3.post1, fixed in commit 0816ef1, contains a symlink attack vulnerability in the download_and_copy() function within hopper/setup.py that extracts NVIDIA toolchain archives without validating symlinks or filtering tar members. A local attacker can pre-plant a symlink in the predictable cache directory to redirect extracted binaries to an attacker-chosen location, enabling arbitrary file write with victim privileges during build time.",
"id": "GHSA-w9r7-4gwr-j959",
"modified": "2026-07-14T00:31:04Z",
"published": "2026-07-14T00:31:04Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-62239"
},
{
"type": "WEB",
"url": "https://github.com/Dao-AILab/flash-attention/issues/2637"
},
{
"type": "WEB",
"url": "https://github.com/Dao-AILab/flash-attention/pull/2702"
},
{
"type": "WEB",
"url": "https://github.com/Dao-AILab/flash-attention/commit/0816ef12f424c6ec94b057a72c275b14f6e6edb2"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/flashattention-symlink-attack-via-tarfile-extractall-in-hopper-setup-py"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-W9WQ-P2WH-M5PX
Vulnerability from github – Published: 2022-05-17 05:52 – Updated: 2022-05-17 05:52
VLAI
Details
** DISPUTED ** firehol in firehol 1.256 allows local users to overwrite arbitrary files via a symlink attack on (1) /tmp/.firehol-tmp-#####-- and (2) /tmp/firehol.conf temporary files. NOTE: the vendor disputes this vulnerability, stating that an attack "would require an attacker to create 1073741824*PID-RANGE symlinks."
{
"affected": [],
"aliases": [
"CVE-2008-4953"
],
"database_specific": {
"cwe_ids": [
"CWE-59"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2008-11-05T15:00:00Z",
"severity": "MODERATE"
},
"details": "** DISPUTED ** firehol in firehol 1.256 allows local users to overwrite arbitrary files via a symlink attack on (1) /tmp/.firehol-tmp-#####-*-* and (2) /tmp/firehol.conf temporary files. NOTE: the vendor disputes this vulnerability, stating that an attack \"would require an attacker to create 1073741824*PID-RANGE symlinks.\"",
"id": "GHSA-w9wq-p2wh-m5px",
"modified": "2022-05-17T05:52:31Z",
"published": "2022-05-17T05:52:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-4953"
},
{
"type": "WEB",
"url": "https://bugs.gentoo.org/show_bug.cgi?id=235770"
},
{
"type": "WEB",
"url": "http://bugs.debian.org/496424"
},
{
"type": "WEB",
"url": "http://dev.gentoo.org/~rbu/security/debiantemp/firehol"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2008/10/30/2"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-W9XP-GH5G-RF6P
Vulnerability from github – Published: 2022-05-24 19:02 – Updated: 2022-05-24 19:02
VLAI
Details
Privilege Escalation vulnerability in the File Lock component of McAfee Total Protection (MTP) prior to 16.0.32 allows a local user to gain elevated privileges by manipulating a symbolic link in the IOCTL interface.
Severity
7.8 (High)
{
"affected": [],
"aliases": [
"CVE-2021-23872"
],
"database_specific": {
"cwe_ids": [
"CWE-269",
"CWE-59"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-05-12T09:15:00Z",
"severity": "HIGH"
},
"details": "Privilege Escalation vulnerability in the File Lock component of McAfee Total Protection (MTP) prior to 16.0.32 allows a local user to gain elevated privileges by manipulating a symbolic link in the IOCTL interface.",
"id": "GHSA-w9xp-gh5g-rf6p",
"modified": "2022-05-24T19:02:16Z",
"published": "2022-05-24T19:02:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-23872"
},
{
"type": "WEB",
"url": "http://service.mcafee.com/FAQDocument.aspx?\u0026id=TS103146"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-WC24-5J7X-RP2X
Vulnerability from github – Published: 2022-05-24 17:27 – Updated: 2022-05-24 17:27
VLAI
Details
In KDE Ark before 20.08.1, a crafted TAR archive with symlinks can install files outside the extraction directory, as demonstrated by a write operation to a user's home directory.
Severity
{
"affected": [],
"aliases": [
"CVE-2020-24654"
],
"database_specific": {
"cwe_ids": [
"CWE-59"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-09-02T17:15:00Z",
"severity": "MODERATE"
},
"details": "In KDE Ark before 20.08.1, a crafted TAR archive with symlinks can install files outside the extraction directory, as demonstrated by a write operation to a user\u0027s home directory.",
"id": "GHSA-wc24-5j7x-rp2x",
"modified": "2022-05-24T17:27:14Z",
"published": "2022-05-24T17:27:14Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-24654"
},
{
"type": "WEB",
"url": "https://github.com/KDE/ark/commit/8bf8c5ef07b0ac5e914d752681e470dea403a5bd"
},
{
"type": "WEB",
"url": "https://bugzilla.suse.com/show_bug.cgi?id=1175857"
},
{
"type": "WEB",
"url": "https://kde.org/info/security/advisory-20200827-1.txt"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2022/05/msg00026.html"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LXMMXNJDYOCJRZTESIUGHG6CS4RJKECX"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/YJOZ6YRNPZX5MJGVBMOCOA7N6Z4EU2OK"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/202010-06"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/202101-06"
},
{
"type": "WEB",
"url": "https://usn.ubuntu.com/4482-1"
},
{
"type": "WEB",
"url": "https://www.debian.org/security/2020/dsa-4759"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00001.html"
}
],
"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:N",
"type": "CVSS_V3"
}
]
}
Mitigation MIT-48.1
Architecture and Design
Strategy: Separation of Privilege
- Follow the principle of least privilege when assigning access rights to entities in a software system.
- Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
CAPEC-132: Symlink Attack
An adversary positions a symbolic link in such a manner that the targeted user or application accesses the link's endpoint, assuming that it is accessing a file with the link's name.
CAPEC-17: Using Malicious Files
An attack of this type exploits a system's configuration that allows an adversary to either directly access an executable file, for example through shell access; or in a possible worst case allows an adversary to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
CAPEC-35: Leverage Executable Code in Non-Executable Files
An attack of this type exploits a system's trust in configuration and resource files. When the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high.
CAPEC-76: Manipulating Web Input to File System Calls
An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.