Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V5 - File Handling Path canonicalization, traversal prevention
MITRE ATT&CK
2 techniques across 2 tactics: Discovery, Collection The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A remote attacker could access files and directories outside the intended path by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
NLTK Downloader before 3.4.5 is vulnerable to a directory traversal, allowing attackers to write arbitrary files via a ../ (dot dot slash) in an NLTK package (ZIP archive) that is mishandled during. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Validate and canonicalize file paths. Use chroot or sandboxing. Reject input containing path separators or '../' sequences.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in pypi
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Path Traversal (CWE-22), which allows attackers to access files and directories outside the intended path. NLTK Downloader before 3.4.5 is vulnerable to a directory traversal, allowing attackers to write arbitrary files via a ../ (dot dot slash) in an NLTK package (ZIP archive) that is mishandled during extraction. Affected products include: Nltk. Version information: before 3.4.5.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
NLTK Downloader before 3.4.5 is vulnerable to a directory traversal, allowing attackers to write arbitrary files via a ../ (dot dot slash) in an NLTK package (ZIP archive) that is mishandled during extraction.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Path traversal exploits occur when applications use user-controlled input to construct file system paths without proper validation.
Affected Products (CPE)NVD
Arbitrary code execution in the Natural Language Toolkit (NLTK) before 3.10.3 allows attackers to bypass the library's p
Arbitrary code execution in NLTK (Natural Language Toolkit) through 3.9.4 allows attackers to run Python code when a vic
Arbitrary code execution in the NLTK (Natural Language Toolkit) Python library affects all versions through its data dow
StreamBackedCorpusView in NLTK before 3.10.0 allows arbitrary local file reads by calling Python's builtins.open() direc
Symlink-based path traversal in NLTK's FramenetCorpusReader before version 3.10.2 permits attackers with write access to
Unbounded recursion in NLTK's JSONTaggedDecoder.decode_obj() (nltk/jsontags.py) allows unauthenticated remote attackers
Path traversal and pickle deserialization protections in NLTK before 3.10.0 are effectively disabled by default - pathse
XML Entity Expansion (Billion Laughs) in NLTK before 3.10.3 allows unauthenticated remote attackers to cause denial of s
Server-side request forgery in NLTK before 3.10.3 allows unauthenticated remote attackers to reach internal HTTP service
Symlink escape in NLTK's CorpusReader.open() allows local attackers to read arbitrary files outside the designated corpu
Path traversal in NLTK's FramenetCorpusReader and NKJPCorpusReader (all versions before 3.10.0) enables unauthenticated
NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research a
Exploit-DB